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Li Q, Wu K, Zhu H, Yang Y, He S, Lian T. Charge Transfer from Quantum-Confined 0D, 1D, and 2D Nanocrystals. Chem Rev 2024; 124:5695-5763. [PMID: 38629390 PMCID: PMC11082908 DOI: 10.1021/acs.chemrev.3c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/29/2024] [Accepted: 04/02/2024] [Indexed: 05/09/2024]
Abstract
The properties of colloidal quantum-confined semiconductor nanocrystals (NCs), including zero-dimensional (0D) quantum dots, 1D nanorods, 2D nanoplatelets, and their heterostructures, can be tuned through their size, dimensionality, and material composition. In their photovoltaic and photocatalytic applications, a key step is to generate spatially separated and long-lived electrons and holes by interfacial charge transfer. These charge transfer properties have been extensively studied recently, which is the subject of this Review. The Review starts with a summary of the electronic structure and optical properties of 0D-2D nanocrystals, followed by the advances in wave function engineering, a novel way to control the spatial distribution of electrons and holes, through their size, dimension, and composition. It discusses the dependence of NC charge transfer on various parameters and the development of the Auger-assisted charge transfer model. Recent advances in understanding multiple exciton generation, decay, and dissociation are also discussed, with an emphasis on multiple carrier transfer. Finally, the applications of nanocrystal-based systems for photocatalysis are reviewed, focusing on the photodriven charge separation and recombination processes that dictate the function and performance of these materials. The Review ends with a summary and outlook of key remaining challenges and promising future directions in the field.
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Affiliation(s)
- Qiuyang Li
- Department
of Physics, University of Michigan, 450 Church St, Ann Arbor, Michigan 48109, United States
| | - Kaifeng Wu
- State
Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation
Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiming Zhu
- Department
of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Ye Yang
- The
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM
(Collaborative Innovation Center of Chemistry for Energy Materials),
College of Chemistry & Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Sheng He
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Tianquan Lian
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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2
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Liao C, Tang L, Jia Y, Sun S, Yang H, Xu J, Gu Z. Slow Auger Recombination in Ag 2Se Colloidal Quantum Dots. NANO LETTERS 2023; 23:9865-9871. [PMID: 37871258 DOI: 10.1021/acs.nanolett.3c02770] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Efficient Auger recombination (AR) presents a significant challenge for the advancement of colloidal quantum dot (QD)-based devices involving multiexcitons. Here, the AR dynamics of near-infrared Ag2Se QDs were studied through transient absorption experiments. As the QD radius increases from 0.9 to 2.5 nm, the biexciton lifetime (τ2) of Ag2Se QDs increases from 35 to 736 ps, which is approximately 10 times longer than that of comparable-sized CdSe and PbSe QDs. A qualitative analysis based on observables indicates that the slow Auger rate is primarily attributed to the low density of the final states. The biexciton lifetime and triexciton lifetime (τ3) of Ag2Se QDs follow R3 and R2.6 dependence, respectively. Moreover, the ratio of τ2/τ3 is ∼2.3-3.2, which is markedly lower than the value expected from statistical scaling (4.5). These findings suggest that environmentally friendly Ag2Se QDs can serve as excellent candidates for low-threshold lasers and third-generation photovoltaics utilizing carrier multiplication.
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Affiliation(s)
- Chen Liao
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Luping Tang
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
- SEU-FEI Nano-Pico Center, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Yunzhe Jia
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Shaoling Sun
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Haoran Yang
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Jie Xu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Zixuan Gu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
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3
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Synthesis of Metal–Organic Frameworks Quantum Dots Composites as Sensors for Endocrine-Disrupting Chemicals. Int J Mol Sci 2022; 23:ijms23147980. [PMID: 35887328 PMCID: PMC9324456 DOI: 10.3390/ijms23147980] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 11/17/2022] Open
Abstract
Hazardous chemical compounds such as endocrine-disrupting chemicals (EDCs) are widespread and part of the materials we use daily. Among these compounds, bisphenol A (BPA) is the most common endocrine-disrupting chemical and is prevalent due to the chemical raw materials used to manufacture thermoplastic polymers, rigid foams, and industrial coatings. General exposure to endocrine-disrupting chemicals constitutes a serious health hazard, especially to reproductive systems, and can lead to transgenerational diseases in adults due to exposure to these chemicals over several years. Thus, it is necessary to develop sensors for early detection of endocrine-disrupting chemicals. In recent years, the use of metal–organic frameworks (MOFs) as sensors for EDCs has been explored due to their distinctive characteristics, such as wide surface area, outstanding chemical fastness, structural tuneability, gas storage, molecular separation, proton conductivity, and catalyst activity, among others which can be modified to sense hazardous environmental pollutants such as EDCs. In order to improve the versatility of MOFs as sensors, semiconductor quantum dots have been introduced into the MOF pores to form metal–organic frameworks/quantum dots composites. These composites possess a large optical absorption coefficient, low toxicity, direct bandgap, formidable sensing capacity, high resistance to change under light and tunable visual qualities by varying the size and compositions, which make them useful for applications as sensors for probing of dangerous and risky environmental contaminants such as EDCs and more. In this review, we explore various synthetic strategies of (MOFs), quantum dots (QDs), and metal–organic framework quantum dots composites (MOFs@QDs) as efficient compounds for the sensing of ecological pollutants, contaminants, and toxicants such as EDCs. We also summarize various compounds or materials used in the detection of BPA as well as the sensing ability and capability of MOFs, QDs, and MOFs@QDs composites that can be used as sensors for EDCs and BPA.
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4
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Mittal M, Dana J, Lübkemann F, Ghosh HN, Bigall NC, Sapra S. Insight into morphology dependent charge carrier dynamics in ZnSe-CdS nanoheterostructures. Phys Chem Chem Phys 2022; 24:8519-8528. [PMID: 35348140 DOI: 10.1039/d1cp05872j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Semiconductor nanoheterostructures (NHSs) are being increasingly used for the photocatalytic conversion of solar energy in which photo-induced charge separation is an essential step and hence it is necessary to understand the effect of various factors such as size, shape, and composition on the charge transfer dynamics. Ultrafast transient absorption spectroscopy is used to investigate the nature and dynamics of photo-induced charge transfer processes in ZnSe-CdS NHSs of different morphologies such as nanospheres (NSs), nanorods (NRs), and nanoplates (NPs). It demonstrates the fast separation of charge carriers and localization of both charges in adjacent semiconductors, resulting in the formation of a charge-separated (CS) state. The lifetime of the charge-separated state follows the order of NSs < NPs < NRs, emphasizing the effect of morphology on the enhancement of photo-induced charge separation and suppression of backward recombination. The separated charge carriers have been utilized in visible light driven hydrogen production and the hydrogen generation activity follows the same order as that for the lifetime of the CS state, underlining the role of charge separation efficiency. Therefore, the variation of the morphology of NHSs plays a significant role in their charge carrier dynamics and hence the photocatalytic hydrogen production activity.
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Affiliation(s)
- Mona Mittal
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. .,Deparment of Chemistry, University Institute of Science, Chandigarh University, Gharaun, Punjab 140413, India
| | - Jayanta Dana
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400085, India
| | - Franziska Lübkemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, D-30167 Hannover, Germany
| | - Hirendra N Ghosh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400085, India.,Institute of Nano Science and Technology, Knowledge City, Sector - 81, Mohali, Punjab 140306, India
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, D-30167 Hannover, Germany
| | - Sameer Sapra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
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5
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Marri I, Ossicini S. Multiple exciton generation in isolated and interacting silicon nanocrystals. NANOSCALE 2021; 13:12119-12142. [PMID: 34250528 DOI: 10.1039/d1nr01747k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
An important challenge in the field of renewable energy is the development of novel nanostructured solar cell devices which implement low-dimensional materials to overcome the limits of traditional photovoltaic systems. For optimal energy conversion in photovoltaic devices, one important requirement is that the full energy of the solar spectrum is effectively used. In this context, the possibility of exploiting features and functionalities induced by the reduced dimensionality of the nanocrystalline phase, in particular by the quantum confinement of the electronic density, can lead to a better use of the carrier excess energy and thus to an increment of the thermodynamic conversion efficiency of the system. Carrier multiplication, i.e. the generation of multiple electron-hole pairs after absorption of one single high-energy photon (with energy at least twice the energy gap of the system), can be exploited to maximize cell performance, promoting a net reduction of loss mechanisms. Over the past fifteen years, carrier multiplication has been recorded in a large variety of semiconductor nanocrystals and other nanostructures. Owing to the role of silicon in solar cell applications, the mission of this review is to summarize the progress in this fascinating research field considering carrier multiplication in Si-based low-dimensional systems, in particular Si nanocrystals, both from the experimental and theoretical point of view, with special attention given to the results obtained by ab initio calculations.
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Affiliation(s)
- Ivan Marri
- Department of Sciences and Methods for Engineering, University of Modena e Reggio Emilia, 42122 Reggio Emilia, Italy.
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6
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Weidling AM, Turkani VS, Luo B, Schroder KA, Swisher SL. Photonic Curing of Solution-Processed Oxide Semiconductors with Efficient Gate Absorbers and Minimal Substrate Heating for High-Performance Thin-Film Transistors. ACS OMEGA 2021; 6:17323-17334. [PMID: 34278118 PMCID: PMC8280640 DOI: 10.1021/acsomega.1c01421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/15/2021] [Indexed: 05/25/2023]
Abstract
In this study, photonic curing is used to rapidly and effectively convert metal-oxide sol-gels to realize high-quality thin-film transistors (TFTs). Photonic curing offers advantages over conventional thermal processing methods such as ultrashort processing time and compatibility with low-temperature substrates. However, previous work on photonically cured TFTs often results in significant heating of the entire substrate rather than just the thin film at the surface. Here, sol-gel indium zinc oxide (IZO)-based TFTs are photonically cured with efficient gate absorbers requiring as few as five pulses using intense white light delivering radiant energy up to 6 J cm-2. Simulations indicate that the IZO film reaches a peak temperature of ∼590 °C while the back of the substrate stays below 30 °C. The requirements and design guidelines for photonic curing metal-oxide semiconductors for high-performance TFT applications are discussed, focusing on the importance of effective gate absorbers and optimized pulse designs to efficiently and effectively cure sol-gel films. This process yields TFTs with a field-effect mobility of 21.8 cm2 V-1 s-1 and an I on/I off ratio approaching 108, which exceeds the performance of samples annealed at 500 °C for 1 h. This is the best performance and highest metal-oxide conversion for photonically cured oxide TFTs achieved to date that does not significantly heat the entire thickness of the substrate. Importantly, the conversion from sol-gel precursors to the semiconducting metal-oxide phase during photonic curing is on par with thermal annealing, which is a significant improvement over previous pulsed-light processing work. The use of efficient gate absorbers also allows for the reduction in the number of pulses and efficient sol-gel conversion.
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Affiliation(s)
- Adam M. Weidling
- Department
of Electrical and Computer Engineering, University of Minnesota, Twin Cities, 4-174 Keller Hall, 200 Union Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Vikram S. Turkani
- NovaCentrix, 400 Parker Drive, Suite 1110, Austin, Texas 78728, United States
| | - Bing Luo
- Characterization
Facility, University of Minnesota, Twin
Cities, 12 Shepherd Labs,
100 Union Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Kurt A. Schroder
- NovaCentrix, 400 Parker Drive, Suite 1110, Austin, Texas 78728, United States
| | - Sarah L. Swisher
- Department
of Electrical and Computer Engineering, University of Minnesota, Twin Cities, 4-174 Keller Hall, 200 Union Street Southeast, Minneapolis, Minnesota 55455, United States
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7
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Harvey SM, Houck DW, Kirschner MS, Flanders NC, Brumberg A, Leonard AA, Watkins NE, Chen LX, Dichtel WR, Zhang X, Korgel BA, Wasielewski MR, Schaller RD. Transient Lattice Response upon Photoexcitation in CuInSe 2 Nanocrystals with Organic or Inorganic Surface Passivation. ACS NANO 2020; 14:13548-13556. [PMID: 32915540 DOI: 10.1021/acsnano.0c05553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CuInSe2 nanocrystals offer promise for optoelectronics including thin-film photovoltaics and printed electronics. Additive manufacturing methods such as photonic curing controllably sinter particles into quasi-continuous films and offer improved device performance. To gain understanding of nanocrystal response under such processing conditions, we investigate impacts of photoexcitation on colloidal nanocrystal lattices via time-resolved X-ray diffraction. We probe three sizes of particles and two capping ligands (oleylamine and inorganic S2-) to evaluate resultant crystal lattice temperature, phase stability, and thermal dissipation. Elevated fluences produce heating and loss of crystallinity, the onset of which exhibits particle size dependence. We find size-dependent recrystallization and cooling lifetimes ranging from 90 to 200 ps with additional slower cooling on the nanosecond time scale. Sulfide-capped nanocrystals show faster recrystallization and cooling compared to oleylamine-capped nanocrystals. Using these lifetimes, we find interfacial thermal conductivities from 3 to 28 MW/(m2 K), demonstrating that ligand identity strongly influences thermal dissipation.
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Affiliation(s)
- Samantha M Harvey
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
| | - Daniel W Houck
- McKetta Department of Chemical Engineering, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Matthew S Kirschner
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Nathan C Flanders
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Alexandra Brumberg
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Ariel A Leonard
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Chemical Science and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Nicolas E Watkins
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Lin X Chen
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Chemical Science and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - William R Dichtel
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Xiaoyi Zhang
- X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Brian A Korgel
- McKetta Department of Chemical Engineering, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Michael R Wasielewski
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
| | - Richard D Schaller
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
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8
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Debnath T, Ghosh HN. Ternary Metal Chalcogenides: Into the Exciton and Biexciton Dynamics. J Phys Chem Lett 2019; 10:6227-6238. [PMID: 31556303 DOI: 10.1021/acs.jpclett.9b01596] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Intra-band-gap state-induced low-toxicity colloidal I-III-VI ternary metal chalcogenide nanocrystals (NCs) have emerged as promising alternatives to the toxic Cd- and Pb-chalcogenides for different optoelectronic and bioimaging applications. In this Perspective, we provide the primary understanding of the intra-band-gap state-induced photoluminescence (PL) of I-III-VI NCs, specifically CuInS2 and AgInS2, as a function of particle size and composition and correlated with time-resolved PL measurements. The intra-band-gap state-induced ultrafast exciton and biexciton dynamics are discussed in detail to unravel the subpicosecond carrier relaxation dynamics through transient absorption measurement. Furthermore, ultrafast dissociation of the biexciton on Au@CuInS2 hybrid NCs has been revealed to be due to the presence of Au, which has direct relevance to the improvement of the solar cell efficiency. The proper fundamental insight of the ultrafast exciton and biexciton dynamics of these materials will enable utilization of ternary metal chalcogenides in photovoltaic as well as light-emitting devices.
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Affiliation(s)
- Tushar Debnath
- Radiation and Photochemistry Division , Bhabha Atomic Research Centre , Mumbai 400085 , India
| | - Hirendra N Ghosh
- Radiation and Photochemistry Division , Bhabha Atomic Research Centre , Mumbai 400085 , India
- Institute of Nano Science and Technology , Mohali , Punjab 160064 , India
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9
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Limborço H, Salomé PMP, Ribeiro-Andrade R, Teixeira JP, Nicoara N, Abderrafi K, Leitão JP, Gonzalez JC, Sadewasser S. CuInSe 2 quantum dots grown by molecular beam epitaxy on amorphous SiO 2 surfaces. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2019; 10:1103-1111. [PMID: 31165036 PMCID: PMC6541361 DOI: 10.3762/bjnano.10.110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
The currently most efficient polycrystalline solar cells are based on the Cu(In,Ga)Se2 compound as a light absorption layer. However, in view of new concepts of nanostructured solar cells, CuInSe2 nanostructures are of high interest. In this work, we report CuInSe2 nanodots grown through a vacuum-compatible co-evaporation growth process on an amorphous surface. The density, mean size, and peak optical emission energy of the nanodots can be controlled by changing the growth temperature. Scanning transmission electron microscopy measurements confirmed the crystallinity of the nanodots as well as chemical composition and structure compatible with tetragonal CuInSe2. Photoluminescence measurements of CdS-passivated nanodots showed that the nanodots are optoelectronically active with a broad emission extending to energies above the CuInSe2 bulk bandgap and in agreement with the distribution of sizes. A blue-shift of the luminescence is observed as the average size of the nanodots gets smaller, evidencing quantum confinement in all samples. By using simple quantum confinement calculations, we correlate the photoluminescence peak emission energy with the average size of the nanodots.
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Affiliation(s)
- Henrique Limborço
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Pedro MP Salomé
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - Rodrigo Ribeiro-Andrade
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Jennifer P Teixeira
- Departamento de Física and I3N, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Nicoleta Nicoara
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Instituto de Microelectrónica de Madrid (CNM-CSIC), 28760 Madrid, Spain
- QuantaLab, 4715-330 Braga, Portugal
| | - Kamal Abderrafi
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Instituto de Microelectrónica de Madrid (CNM-CSIC), 28760 Madrid, Spain
- Hassan II University of Casablanca, 20663 Casablanca, Morocco
| | - Joaquim P Leitão
- Departamento de Física and I3N, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Juan C Gonzalez
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Sascha Sadewasser
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- QuantaLab, 4715-330 Braga, Portugal
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10
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Ma S, Dong L, Dong H, Wang J, Chen Y, Pang B, Feng J, Yu L, Zhao M. Colloidal Cu2ZnSn(S1-,Se )4-Au nano-heterostructures for inorganic perovskite photovoltaic applications as photocathode alternative. J Colloid Interface Sci 2019; 539:598-608. [DOI: 10.1016/j.jcis.2018.12.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/24/2018] [Accepted: 12/28/2018] [Indexed: 10/27/2022]
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11
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Wang H, Butler DJ, Straus DB, Oh N, Wu F, Guo J, Xue K, Lee JD, Murray CB, Kagan CR. Air-Stable CuInSe 2 Nanocrystal Transistors and Circuits via Post-Deposition Cation Exchange. ACS NANO 2019; 13:2324-2333. [PMID: 30707549 DOI: 10.1021/acsnano.8b09055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Colloidal semiconductor nanocrystals (NCs) are a promising materials class for solution-processable, next-generation electronic devices. However, most high-performance devices and circuits have been achieved using NCs containing toxic elements, which may limit their further device development. We fabricate high mobility CuInSe2 NC field-effect transistors (FETs) using a solution-based, post-deposition, sequential cation exchange process that starts with electronically coupled, thiocyanate (SCN)-capped CdSe NC thin films. First Cu+ is substituted for Cd2+ transforming CdSe NCs to Cu-rich Cu2Se NC films. Next, Cu2Se NC films are dipped into a Na2Se solution to Se-enrich the NCs, thus compensating the Cu-rich surface, promoting fusion of the Cu2Se NCs, and providing sites for subsequent In-dopants. The liquid-coordination-complex trioctylphosphine-indium chloride (TOP-InCl3) is used as a source of In3+ to partially exchange and n-dope CuInSe2 NC films. We demonstrate Al2O3-encapsulated, air-stable CuInSe2 NC FETs with linear (saturation) electron mobilities of 8.2 ± 1.8 cm2/(V s) (10.5 ± 2.4 cm2/(V s)) and with current modulation of 105, comparable to that for high-performance Cd-, Pb-, and As-based NC FETs. The CuInSe2 NC FETs are used as building blocks of integrated inverters to demonstrate their promise for low-cost, low-toxicity NC circuits.
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Affiliation(s)
| | | | | | - Nuri Oh
- Division of Materials Science and Engineering , Hanyang University , Seoul 133-791 , Republic of Korea
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12
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Maiti S, Dana J, Ghosh HN. Correlating Charge‐Carrier Dynamics with Efficiency in Quantum‐Dot Solar Cells: Can Excitonics Lead to Highly Efficient Devices? Chemistry 2018; 25:692-702. [DOI: 10.1002/chem.201801853] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 07/06/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Sourav Maiti
- Radiation & Photochemistry DivisionBhabha Atomic Research Centre Mumbai 400085 India
- Department of ChemistrySavitribai Phule Pune University Ganeshkhind Pune 411007 India
| | - Jayanta Dana
- Radiation & Photochemistry DivisionBhabha Atomic Research Centre Mumbai 400085 India
| | - Hirendra N. Ghosh
- Radiation & Photochemistry DivisionBhabha Atomic Research Centre Mumbai 400085 India
- Institute of Nano Science and Technology Mohali Punjab 160062 India
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13
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Singh A, Lutz L, Ong GK, Bustillo K, Raoux S, Jordan-Sweet JL, Milliron DJ. Controlling Morphology in Polycrystalline Films by Nucleation and Growth from Metastable Nanocrystals. NANO LETTERS 2018; 18:5530-5537. [PMID: 30080050 DOI: 10.1021/acs.nanolett.8b01916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Solution processing of polycrystalline compound semiconductor thin film using nanocrystals as a precursor is considered one of the most promising and economically viable routes for future large-area manufacturing. However, in polycrystalline compound semiconductor films such as Cu2ZnSnS4 (CZTS), grain size, and the respective grain boundaries play a key role in dictating the optoelectronic properties. Various strategies have been employed previously in tailoring the grain size and boundaries (such as ligand exchange) but most require postdeposition thermal annealing at high temperature in the presence of grain growth directing agents (selenium or sulfur vapor with/without Na, K, etc.) to enlarge the grains through sintering. Here, we show a different strategy of controlling grain size by tuning the kinetics of nucleation and the subsequent grain growth in CZTS nanocrystal thin films during a crystalline phase transition. We demonstrate that the activation energy for the phase transition can be varied by utilizing different shapes (spherical and nanorod) of nanocrystals with similar size, composition, and surface chemistry leading to different densities of nucleation sites and, thereby, different grain sizes in the films. Additionally, exchanging the native organic ligands for inorganic surface ligands changes the activation energy for the phase change and substantially changes the grain growth dynamics, while also compositionally modifying the resulting film. This combined approach of using nucleation and growth dynamics and surface chemistry enables us to tune the grain size of polycrystalline CZTS films and customize their electronic properties by compositional engineering.
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Affiliation(s)
- Ajay Singh
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
- The Molecular Foundry , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Lukas Lutz
- The Molecular Foundry , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Gary K Ong
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
- Department of Materials Science and Engineering , University of California-Berkeley , Berkeley , California 94720 , United States
| | - Karen Bustillo
- The Molecular Foundry , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Simone Raoux
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Jean L Jordan-Sweet
- IBM Watson Research Center , 1101 Kitchawan Road , Yorktown Heights , New York 10598 , United States
| | - Delia J Milliron
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
- The Molecular Foundry , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
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14
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Sygletou M, Petridis C, Kymakis E, Stratakis E. Advanced Photonic Processes for Photovoltaic and Energy Storage Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1700335. [PMID: 28837745 DOI: 10.1002/adma.201700335] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/08/2017] [Indexed: 06/07/2023]
Abstract
Solar-energy harvesting through photovoltaic (PV) conversion is the most promising technology for long-term renewable energy production. At the same time, significant progress has been made in the development of energy-storage (ES) systems, which are essential components within the cycle of energy generation, transmission, and usage. Toward commercial applications, the enhancement of the performance and competitiveness of PV and ES systems requires the adoption of precise, but simple and low-cost manufacturing solutions, compatible with large-scale and high-throughput production lines. Photonic processes enable cost-efficient, noncontact, highly precise, and selective engineering of materials via photothermal, photochemical, or photophysical routes. Laser-based processes, in particular, provide access to a plethora of processing parameters that can be tuned with a remarkably high degree of precision to enable innovative processing routes that cannot be attained by conventional approaches. The focus here is on the application of advanced light-driven approaches for the fabrication, as well as the synthesis, of materials and components relevant to PV and ES systems. Besides presenting recent advances on recent achievements, the existing limitations are outlined and future possibilities and emerging prospects discussed.
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Affiliation(s)
- Maria Sygletou
- Institute of Electronic Structure and Laser Foundation for Research and Technology - Hellas, Heraklion, 71110, Crete, Greece
| | - Constantinos Petridis
- Center of Materials Technology and Photonics & Electrical Engineering Department, School of Applied Technology, Technological Educational Institute (TEI) of Crete, Heraklion, 71004, Crete, Greece
| | - Emmanuel Kymakis
- Center of Materials Technology and Photonics & Electrical Engineering Department, School of Applied Technology, Technological Educational Institute (TEI) of Crete, Heraklion, 71004, Crete, Greece
| | - Emmanuel Stratakis
- Institute of Electronic Structure and Laser Foundation for Research and Technology - Hellas, Heraklion, 71110, Crete, Greece
- Department of Materials Science and Technology, University of Crete, Heraklion, 71003, Greece
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15
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Stolle CJ, Lu X, Yu Y, Schaller RD, Korgel BA. Efficient Carrier Multiplication in Colloidal Silicon Nanorods. NANO LETTERS 2017; 17:5580-5586. [PMID: 28762274 DOI: 10.1021/acs.nanolett.7b02386] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Auger recombination lifetimes, absorption cross sections, and the quantum yields of carrier multiplication (CM), or multiexciton generation (MEG), were determined for solvent-dispersed silicon (Si) nanorods using transient absorption spectroscopy (TAS). Nanorods with an average diameter of 7.5 nm and aspect ratios of 6.1, 19.3, and 33.2 were examined. Colloidal Si nanocrystals of similar diameters were also studied for comparison. The nanocrystals and nanorods were passivated with organic ligands by hydrosilylation to prevent surface oxidation and limit the effects of surface trapping of photoexcited carriers. All samples used in the study exhibited relatively efficient photoluminescence. The Auger lifetimes increased with nanorod length, and the nanorods exhibited higher CM quantum yield and efficiency than the nanocrystals with a similar band gap energy Eg. Beyond a critical length, the CM quantum yield decreases. Nanorods with the aspect ratio of 19.3 had the highest CM quantum yield of 1.6 ± 0.2 at 2.9Eg, which corresponded to a multiexciton yield that was twice as high as observed for the spherical nanocrystals.
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Affiliation(s)
- Carl Jackson Stolle
- McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Xiaotang Lu
- McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Yixuan Yu
- McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Richard D Schaller
- Department of Chemistry, Northwestern University , Evanston, Illinois 60439, United States
- Center for Nanoscale Materials, Argonne National Laboratories , Argonne, Illinois 60439, United States
| | - Brian A Korgel
- McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , Austin, Texas 78712, United States
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16
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Pietryga JM, Park YS, Lim J, Fidler AF, Bae WK, Brovelli S, Klimov VI. Spectroscopic and Device Aspects of Nanocrystal Quantum Dots. Chem Rev 2017; 116:10513-622. [PMID: 27677521 DOI: 10.1021/acs.chemrev.6b00169] [Citation(s) in RCA: 390] [Impact Index Per Article: 55.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The field of nanocrystal quantum dots (QDs) is already more than 30 years old, and yet continuing interest in these structures is driven by both the fascinating physics emerging from strong quantum confinement of electronic excitations, as well as a large number of prospective applications that could benefit from the tunable properties and amenability toward solution-based processing of these materials. The focus of this review is on recent advances in nanocrystal research related to applications of QD materials in lasing, light-emitting diodes (LEDs), and solar energy conversion. A specific underlying theme is innovative concepts for tuning the properties of QDs beyond what is possible via traditional size manipulation, particularly through heterostructuring. Examples of such advanced control of nanocrystal functionalities include the following: interface engineering for suppressing Auger recombination in the context of QD LEDs and lasers; Stokes-shift engineering for applications in large-area luminescent solar concentrators; and control of intraband relaxation for enhanced carrier multiplication in advanced QD photovoltaics. We examine the considerable recent progress on these multiple fronts of nanocrystal research, which has resulted in the first commercialized QD technologies. These successes explain the continuing appeal of this field to a broad community of scientists and engineers, which in turn ensures even more exciting results to come from future exploration of this fascinating class of materials.
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Affiliation(s)
- Jeffrey M Pietryga
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Young-Shin Park
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.,Center for High Technology Materials, University of New Mexico , Albuquerque, New Mexico 87131, United States
| | - Jaehoon Lim
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Andrew F Fidler
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Wan Ki Bae
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology , Seoul 02792, Korea
| | - Sergio Brovelli
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , I-20125 Milano, Italy
| | - Victor I Klimov
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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17
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Coughlan C, Ibáñez M, Dobrozhan O, Singh A, Cabot A, Ryan KM. Compound Copper Chalcogenide Nanocrystals. Chem Rev 2017; 117:5865-6109. [PMID: 28394585 DOI: 10.1021/acs.chemrev.6b00376] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defect concentration, including charge carrier concentration and electronic conductivity character, which consequently affects their optoelectronic, optical, and plasmonic properties. This, combined with several metastable crystal phases and stoichiometries and the low energy of formation of defects, makes the reproducible synthesis of these materials, with tunable parameters, remarkable. Further to this, the review captures the progress of the hierarchical assembly of these NCs, which bridges the link between their discrete and collective properties. Their ubiquitous application set has cross-cut energy conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling), sensors (electrochemical, biochemical), biomedical devices (magnetic resonance imaging, X-ray computer tomography), and medical therapies (photochemothermal therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of advances in the synthesis, assembly, and application of these NCs in the past decade has the potential to significantly impact society, both economically and environmentally.
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Affiliation(s)
- Claudia Coughlan
- Department of Chemical Sciences and Bernal Institute, University of Limerick , Limerick, Ireland
| | - Maria Ibáñez
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain
| | - Oleksandr Dobrozhan
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain.,Department of Electronics and Computing, Sumy State University , 2 Rymskogo-Korsakova st., 40007 Sumy, Ukraine
| | - Ajay Singh
- Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Andreu Cabot
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Kevin M Ryan
- Department of Chemical Sciences and Bernal Institute, University of Limerick , Limerick, Ireland
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18
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Das S, Sopha H, Krbal M, Zazpe R, Podzemna V, Prikryl J, Macak JM. Electrochemical Infilling of CuInSe 2 within TiO 2 Nanotube Layers and Subsequent Photoelectrochemical Studies. ChemElectroChem 2017; 4:495-499. [PMID: 28392991 PMCID: PMC5363378 DOI: 10.1002/celc.201600763] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Indexed: 11/24/2022]
Abstract
Anodic self‐organized TiO2 nanotube layers (with different aspect ratios) were electrochemically infilled with CuInSe2 nanocrystals with the aim to prepare heterostructures with a photoelectrochemical response in the visible light. The resulting heterostructure assembly was confirmed by field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X‐ray diffraction (XRD). High incident photon‐to‐electron conversion efficiency values exceeding 55% were obtained in the visible‐light region. The resulting heterostructures show promise as a candidate for solid‐state solar cells.
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Affiliation(s)
- Sayantan Das
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
| | - Hanna Sopha
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
| | - Milos Krbal
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
| | - Raul Zazpe
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
| | - Veronika Podzemna
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
| | - Jan Prikryl
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
| | - Jan M Macak
- Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice Nam. Cs. Legii 565 53002 Pardubice Czech Republic
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19
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Mehmood I, Liu Y, Chen K, Shah AH, Chen W. Mn doped CdS passivated CuInSe2 quantum dot sensitized solar cells with remarkably enhanced photovoltaic efficiency. RSC Adv 2017. [DOI: 10.1039/c7ra04989g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This paper explores that novel architecture of CuInSe2/Mn-CdS exhibits remarkable enhancement in photovoltaic performance of the QDSSCs, which presents an excellent power conversion efficiency of 3.96%.
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Affiliation(s)
- Ikhtisham Mehmood
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing
- School of Materials Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- P. R. China
| | - Yueli Liu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing
- School of Materials Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- P. R. China
| | - Keqiang Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing
- School of Materials Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- P. R. China
| | - Abdul Hakim Shah
- Department of Material Physics and Nanotechnology
- Khushal Khan Khattak University
- Karak 27200
- Pakistan
| | - Wen Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing
- School of Materials Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- P. R. China
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20
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Thiele G, Donsbach C, Nußbruch I, Dehnen S. Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of Chalcogenidoplumbates(II or IV). J Vis Exp 2016. [PMID: 28060345 DOI: 10.3791/54789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The phases of "PbCh2" (Ch = Se, Te) are obtained from solid-state syntheses (i.e., by the fusion of the elements under inert conditions in silica glass ampules). Reduction of such phases by elemental alkaline metals in amines affords crystalline chalcogenidoplumbate(II) salts comprised of [PbTe3]2- or [Pb2Ch3]2- anions, depending upon which sequestering agent for the cations is present: crown ethers, like 18-crown-6, or cryptands, like [2.2.2]crypt. Reactions of solutions of such anions with transition-metal compounds yield (poly-)chalcogenide anions or transition-metal chalcogenide clusters, including one with a µ-PbSe ligand (i.e., the heaviest-known CO homolog). In contrast, the solid-state synthesis of a phase of the nominal composition "K2PbSe2" by successive reactions of the elements and by the subsequent solvothermal treatment in amines yields the first non-oxide/halide inorganic lead(IV) compound: a salt of the ortho-selenidoplumbate(IV) anion [PbSe4]4-. This was unexpected due to the redox potentials of Pb(IV) and Se(-II). Such methods can further be applied to other elemental combinations, leading to the formation of solutions with binary [HgTe2]2- or [BiSe3]3- anions, or to large-scale syntheses of K2Hg2Se3 or K3BiSe3 via the solid-state route. All compounds are characterized by single-crystal X-ray diffraction and elemental analysis; solutions of plumbate salts can be investigated by 205Pb and 77Se or 127Te NMR techniques. Quantum chemical calculations using density functional theory methods enable energy comparisons. They further allow for insights into the electronic configuration and thus, the bonding situation. Molecular Rh-containing Chevrel-type compounds were found to exhibit delocalized mixed valence, whereas similar telluridopalladate anions are electron-precise; the cluster with the µ-PbSe ligand is energetically favored over a hypothetical CO analog, in line with the unsuccessful attempt at its synthesis. The stability of formal Pb(IV) within the [PbSe4]4- anion is mainly due to a suitable stabilization within the crystal lattice.
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Affiliation(s)
- Günther Thiele
- Department of Chemistry, University of California, Berkeley
| | - Carsten Donsbach
- Fachbereich Chemie, Philipps-Universität Marburg and Wissenschaftliches Zentrum für Materialwissenschaften
| | - Isabell Nußbruch
- Fachbereich Chemie, Philipps-Universität Marburg and Wissenschaftliches Zentrum für Materialwissenschaften
| | - Stefanie Dehnen
- Fachbereich Chemie, Philipps-Universität Marburg and Wissenschaftliches Zentrum für Materialwissenschaften;
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21
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22
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Rivera-González N, Chauhan S, Watson DF. Aminoalkanoic Acids as Alternatives to Mercaptoalkanoic Acids for the Linker-Assisted Attachment of Quantum Dots to TiO2. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9206-9215. [PMID: 27541724 DOI: 10.1021/acs.langmuir.6b02704] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Linear aminoalkanoic acids (AAAs) and mercaptoalkanoic acids (MAAs) were characterized as bifunctional ligands to tether CdSe QDs to nanocrystalline TiO2 thin films and to mediate excited-state electron transfer (ET) from the QDs to TiO2 nanoparticles. The adsorption of 12-aminododecanoic acid (ADA) and 12-mercaptododecanoic acid (ADA) to TiO2 followed the Langmuir adsorption isotherm. Surface adduct formation constants (Kad) were ∼10(4) M(-1); saturation amounts of the ligands per projected surface area of TiO2 (Γ0) were ∼10(-7) mol cm(-2). Both Kad and Γ0 differed by 20% or less for the two linkers. CdSe QDs adhered to ADA- and MDA-functionalized TiO2 films; data were well modeled by the Langmuir adsorption isotherm and Langmuir kinetics. For ADA- and MDA-mediated assembly values of Kad were (1.8 ± 0.4) × 10(6) and (2.4 ± 0.4) × 10(6) M(-1), values of Γ0 were (1.6 ± 0.3) × 10(-9) and (1.2 ± 0.1) × 10(-9) mol cm(-2), and rate constants were (14 ± 5) and (60 ± 20) M(-1) s(-1), respectively. Thus, the thermodynamics and kinetics of linker-assisted assembly were slightly more favorable for MDA than for ADA. Steady-state and time-resolved emission spectroscopy revealed that electrons were transferred from both band-edge and surface states of CdSe QDs to TiO2 with rate constants (ket) of ∼10(7) s(-1). ET was approximately twice as fast through thiol-bearing linker 4-mercaptobutyric acid (MBA) as through amine-bearing linker 4-aminobutyric acid (ABA). Photoexcited QDs transferred holes to adsorbed MBA. In contrast, ABA did not scavenge photogenerated holes from CdSe QDs, which maximized the separation of charges following ET. Additionally, ABA shifted electron-trapping surface states to higher energies, minimizing the loss of potential energy of electrons prior to ET. These trade-offs involving the kinetics and thermodynamics of linker-assisted assembly; the driving force, rate constant, and efficiency of ET; and the extent of photoinduced charge separation can inform the selection bifunctional ligands to tether QDs to surfaces.
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Affiliation(s)
- Natalia Rivera-González
- Department of Chemistry, University at Buffalo, The State University of New York , Buffalo, New York 14260-3000, United States
| | - Saurabh Chauhan
- Department of Chemistry, University at Buffalo, The State University of New York , Buffalo, New York 14260-3000, United States
| | - David F Watson
- Department of Chemistry, University at Buffalo, The State University of New York , Buffalo, New York 14260-3000, United States
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23
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Dana J, Debnath T, Ghosh HN. Involvement of Sub-Bandgap States in Subpicosecond Exciton and Biexciton Dynamics of Ternary AgInS2 Nanocrystals. J Phys Chem Lett 2016; 7:3206-3214. [PMID: 27472249 DOI: 10.1021/acs.jpclett.6b01341] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We have synthesized three AgxInS2 (AIS) ternary nanocrystals (NCs), where x varies from 0.25 to 1, and reported their biexcitonic feature which depends on the stoichiometry ratio of Ag/In. The broadening of absorption band and dual photoluminescence in different AIS NCs indicates the existence of Ag-related sub-bandgap (S-states) and antisite states. Ultrafast charge carrier dynamics in AIS NCs that involve multiple states like higher excited state, band-edge, Ag-related sub-bandgap, and antisite states have been carried out by employing femtosecond transient absorption spectroscopy, which strongly depends on Ag/In ratio. The probe-induced biexcitonic feature that originated from antisite state has been observed in these AIS NCs even at low pump fluency (<N> = ∼0.2). The enhancement of binding energy of biexciton and slow down of electron cooling dynamics has been demonstrated by gradual increment of pump fluence as well as with different stoichiometry of Ag and In.
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Affiliation(s)
- Jayanta Dana
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - Tushar Debnath
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - Hirendra N Ghosh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
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24
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Swart I, Liljeroth P, Vanmaekelbergh D. Scanning probe microscopy and spectroscopy of colloidal semiconductor nanocrystals and assembled structures. Chem Rev 2016; 116:11181-219. [PMID: 26900754 DOI: 10.1021/acs.chemrev.5b00678] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Colloidal semiconductor nanocrystals become increasingly important in materials science and technology, due to their optoelectronic properties that are tunable by size. The measurement and understanding of their energy levels is key to scientific and technological progress. Here we review how the confined electronic orbitals and related energy levels of individual semiconductor quantum dots have been measured by means of scanning tunneling microscopy and spectroscopy. These techniques were originally developed for flat conducting surfaces, but they have been adapted to investigate the atomic and electronic structure of semiconductor quantum dots. We compare the results obtained on colloidal quantum dots with those on comparable solid-state ones. We also compare the results obtained with scanning tunneling spectroscopy with those of optical spectroscopy. The first three sections provide an introduction to colloidal quantum dots, and a theoretical basis to be able to understand tunneling spectroscopy on dots attached to a conducting surface. In sections 4 and 5 , we review the work performed on lead-chalcogenide nanocrystals and on colloidal quantum dots and rods of II-VI compounds, respectively. In section 6 , we deal with colloidal III-V nanocrystals and compare the results with their self-assembled counter parts. In section 7 , we review the work on other types of semiconductor quantum dots, especially on Si and Ge nanocrystals.
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Affiliation(s)
- Ingmar Swart
- Debye Institute for Nanomaterials Science, Chemistry Department, University of Utrecht , Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Peter Liljeroth
- Department of Applied Physics, Aalto University School of Science , PO Box 15100, 00076 Aalto, Finland
| | - Daniel Vanmaekelbergh
- Debye Institute for Nanomaterials Science, Chemistry Department, University of Utrecht , Princetonplein 5, 3584 CC Utrecht, The Netherlands
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25
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Chauhan S, Watson DF. Photoinduced electron transfer from quantum dots to TiO2: elucidating the involvement of excitonic and surface states. Phys Chem Chem Phys 2016; 18:20466-75. [DOI: 10.1039/c6cp03813a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
CdSe QDs transfer electrons from band-edge and surface states to TiO2; core/shell CdSe/ZnS QDs transfer electrons exclusively from band-edge states.
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Affiliation(s)
- Saurabh Chauhan
- Department of Chemistry
- University at Buffalo
- The State University of New York
- Buffalo
- USA
| | - David F. Watson
- Department of Chemistry
- University at Buffalo
- The State University of New York
- Buffalo
- USA
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26
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Zhang X, Zhang Y, Wu H, Yan L, Wang Z, Zhao J, Yu WW, Rogach AL. PbSe quantum dot films with enhanced electron mobility employed in hybrid polymer/nanocrystal solar cells. RSC Adv 2016. [DOI: 10.1039/c6ra01830k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We explore two strategies to improve the performance of hybrid solar cells fabricated using poly(3-hexylthiophene) (P3HT) and colloidal PbSe nanocrystals, which have reached a 1 sun power conversion efficiency of 2.9%.
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Affiliation(s)
- Xiaoyu Zhang
- State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering
- Jilin University
- Changchun 130012
- China
- Department of Physics and Materials Science and Centre for Functional Photonics (CFP)
| | - Yu Zhang
- State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering
- Jilin University
- Changchun 130012
- China
| | - Hua Wu
- State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering
- Jilin University
- Changchun 130012
- China
| | - Long Yan
- State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering
- Jilin University
- Changchun 130012
- China
| | - Zhenguang Wang
- Department of Physics and Materials Science and Centre for Functional Photonics (CFP)
- City University of Hong Kong
- Kowloon
- China
| | - Jun Zhao
- College of Material Science and Engineering
- Qingdao University of Science and Technology
- Qingdao 266042
- China
- Department of Chemistry and Physics
| | - William W. Yu
- State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering
- Jilin University
- Changchun 130012
- China
- College of Material Science and Engineering
| | - Andrey L. Rogach
- Department of Physics and Materials Science and Centre for Functional Photonics (CFP)
- City University of Hong Kong
- Kowloon
- China
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27
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Kagan CR, Murray CB. Charge transport in strongly coupled quantum dot solids. NATURE NANOTECHNOLOGY 2015; 10:1013-26. [PMID: 26551016 DOI: 10.1038/nnano.2015.247] [Citation(s) in RCA: 241] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 09/21/2015] [Indexed: 05/20/2023]
Abstract
The emergence of high-mobility, colloidal semiconductor quantum dot (QD) solids has triggered fundamental studies that map the evolution from carrier hopping through localized quantum-confined states to band-like charge transport in delocalized and hybridized states of strongly coupled QD solids, in analogy with the construction of solids from atoms. Increased coupling in QD solids has led to record-breaking performance in QD devices, such as electronic transistors and circuitry, optoelectronic light-emitting diodes, photovoltaic devices and photodetectors, and thermoelectric devices. Here, we review the advances in synthesis, assembly, ligand treatments and doping that have enabled high-mobility QD solids, as well as the experiments and theory that depict band-like transport in the QD solid state. We also present recent QD devices and discuss future prospects for QD materials and device design.
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Affiliation(s)
- Cherie R Kagan
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Christopher B Murray
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Kim JY, Yang J, Yu JH, Baek W, Lee CH, Son HJ, Hyeon T, Ko MJ. Highly Efficient Copper-Indium-Selenide Quantum Dot Solar Cells: Suppression of Carrier Recombination by Controlled ZnS Overlayers. ACS NANO 2015; 9:11286-95. [PMID: 26431392 DOI: 10.1021/acsnano.5b04917] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Copper-indium-selenide (CISe) quantum dots (QDs) are a promising alternative to the toxic cadmium- and lead-chalcogenide QDs generally used in photovoltaics due to their low toxicity, narrow band gap, and high absorption coefficient. Here, we demonstrate that the photovoltaic performance of CISe QD-sensitized solar cells (QDSCs) can be greatly enhanced simply by optimizing the thickness of ZnS overlayers on the QD-sensitized TiO2 electrodes. By roughly doubling the thickness of the overlayers compared to the conventional one, conversion efficiency is enhanced by about 40%. Impedance studies reveal that the thick ZnS overlayers do not affect the energetic characteristics of the photoanode, yet enhance the kinetic characteristics, leading to more efficient photovoltaic performance. In particular, both interfacial electron recombination with the electrolyte and nonradiative recombination associated with QDs are significantly reduced. As a result, our best cell yields a conversion efficiency of 8.10% under standard solar illumination, a record high for heavy metal-free QD solar cells to date.
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Affiliation(s)
- Jae-Yup Kim
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul, 136-791, Republic of Korea
| | - Jiwoong Yang
- Center for Nanoparticle Research, Institute for Basic Science (IBS) , Seoul, 151-742, Republic of Korea
- School of Chemical and Biological Engineering, Seoul National University , Seoul, 151-742, Republic of Korea
| | - Jung Ho Yu
- Center for Nanoparticle Research, Institute for Basic Science (IBS) , Seoul, 151-742, Republic of Korea
- School of Chemical and Biological Engineering, Seoul National University , Seoul, 151-742, Republic of Korea
| | - Woonhyuk Baek
- Center for Nanoparticle Research, Institute for Basic Science (IBS) , Seoul, 151-742, Republic of Korea
- School of Chemical and Biological Engineering, Seoul National University , Seoul, 151-742, Republic of Korea
| | - Chul-Ho Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University , Seoul, 136-701, Republic of Korea
| | - Hae Jung Son
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul, 136-791, Republic of Korea
| | - Taeghwan Hyeon
- Center for Nanoparticle Research, Institute for Basic Science (IBS) , Seoul, 151-742, Republic of Korea
- School of Chemical and Biological Engineering, Seoul National University , Seoul, 151-742, Republic of Korea
| | - Min Jae Ko
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul, 136-791, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University , Seoul, 136-701, Republic of Korea
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29
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Paglia F, Vak D, van Embden J, Chesman ASR, Martucci A, Jasieniak JJ, Della Gaspera E. Photonic Sintering of Copper through the Controlled Reduction of Printed CuO Nanocrystals. ACS APPLIED MATERIALS & INTERFACES 2015; 7:25473-8. [PMID: 26503740 DOI: 10.1021/acsami.5b08430] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The ability to control chemical reactions using ultrafast light exposure has the potential to dramatically advance materials and their processing toward device integration. In this study, we show how intense pulsed light (IPL) can be used to trigger and modulate the chemical transformations of printed copper oxide features into metallic copper. By varying the energy of the IPL, CuO films deposited from nanocrystal inks can be reduced to metallic Cu via a Cu2O intermediate using single light flashes of 2 ms duration. Moreover, the morphological transformation from isolated Cu nanoparticles to fully sintered Cu films can also be controlled by selecting the appropriate light intensity. The control over such transformations enables for the fabrication of sintered Cu electrodes that show excellent electrical and mechanical properties, good environmental stability, and applications in a variety of flexible devices.
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Affiliation(s)
- Francesco Paglia
- CSIRO Manufacturing , Bayview Avenue, Clayton, Victoria 3168, Australia
- Dipartimento di Ingegneria Industriale Via Marzolo 9, Universita' di Padova , 35131 Padova, Italy
| | - Doojin Vak
- CSIRO Manufacturing , Bayview Avenue, Clayton, Victoria 3168, Australia
| | - Joel van Embden
- School of Applied Science, RMIT University , Melbourne, Victoria 3000, Australia
| | | | - Alessandro Martucci
- Dipartimento di Ingegneria Industriale Via Marzolo 9, Universita' di Padova , 35131 Padova, Italy
| | - Jacek J Jasieniak
- Department of Materials Science and Engineering, Monash University , Clayton, Victoria 3800, Australia
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30
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Debnath T, Maiti S, Maity P, Ghosh HN. Subpicosecond Exciton Dynamics and Biexcitonic Feature in Colloidal CuInS2 Nanocrystals: Role of In-Cu Antisite Defects. J Phys Chem Lett 2015; 6:3458-65. [PMID: 26273721 DOI: 10.1021/acs.jpclett.5b01767] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Charge carrier dynamics of multinary quantum dots like CuInS2 (CIS) nanocrystals (NCs) is not clearly understood, especially in ultrafast time scales. Herein we have synthesized colloidal CIS NCs that show defect-induced emission between donor (antisite) and acceptor (internal/surface) states as indicated from steady-state and time-resolved photoluminescence (PL) measurements. Subpicosecond transient absorption (TA) spectra of CIS NCs reveal a gradient of electronic states that exists above the conduction band edge. The electron cooling rate has been determined to be ∼0.1-0.15 eV/ps. The cascade of electron cooling dynamics was monitored after following the TA kinetics at different electronic states. Interestingly, the kinetics at the antisite state unveil a biexcitonic feature, which has been enlightened through a probe-induced biexciton mechanism. With progressively higher fluence (⟨N⟩), the biexciton binding energy increases, and the electron cooling to the antisite state considerably slows down. Extra energy released during Auger recombination of bi/multiexcitons are used to re-excite the electron to a further high energy level, resulting in longer electron cooling time to the antisite states.
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Affiliation(s)
- Tushar Debnath
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - Sourav Maiti
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - Partha Maity
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - Hirendra N Ghosh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
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31
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Treml BE, Robbins AB, Whitham K, Smilgies DM, Thompson MO, Hanrath T. Processing-Structure-Property Relationships in Laser-Annealed PbSe Nanocrystal Thin Films. ACS NANO 2015; 9:4096-4102. [PMID: 25787088 DOI: 10.1021/acsnano.5b00167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
As nanocrystal (NC) synthesis techniques and device architectures advance, it becomes increasingly apparent that new ways of connecting NCs with each other and their external environment are required to realize their considerable potential. Enhancing inter-NC coupling by thermal annealing has been a long-standing challenge. Conventional thermal annealing approaches are limited by the challenge of annealing the NC at sufficiently high temperatures to remove surface-bound ligands while at the same time limiting the thermal budget to prevent large-scale aggregation. Here we investigate nonequilibrium laser annealing of NC thin films that enables separation of the kinetic and thermodynamic aspects of nanocrystal fusion. We show that laser annealing of NC assemblies on nano- to microsecond time scales can transform initially isolated NCs in a thin film into an interconnected structure in which proximate dots "just touch". We investigate both pulsed laser annealing and laser spike annealing and show that both annealing methods can produce "confined-but-connected" nanocrystal films. We develop a thermal transport model to rationalize the differences in resulting film morphologies. Finally we show that the insights gained from study of nanocrystal mono- and bilayers can be extended to three-dimensional NC films. The basic processing-structure-property relationships established in this work provide guidance to future advances in creating functional thin films in which constituent NCs can purposefully interact.
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Affiliation(s)
- Benjamin E Treml
- †Department of Materials Science and Engineering, ‡Cornell High Energy Synchrotron Source, and §School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Andrew B Robbins
- †Department of Materials Science and Engineering, ‡Cornell High Energy Synchrotron Source, and §School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Kevin Whitham
- †Department of Materials Science and Engineering, ‡Cornell High Energy Synchrotron Source, and §School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Detlef-M Smilgies
- †Department of Materials Science and Engineering, ‡Cornell High Energy Synchrotron Source, and §School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Michael O Thompson
- †Department of Materials Science and Engineering, ‡Cornell High Energy Synchrotron Source, and §School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Tobias Hanrath
- †Department of Materials Science and Engineering, ‡Cornell High Energy Synchrotron Source, and §School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
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32
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Draguta S, McDaniel H, Klimov VI. Tuning carrier mobilities and polarity of charge transport in films of CuInSe(x)S(2-x) quantum dots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:1701-1705. [PMID: 25613726 DOI: 10.1002/adma.201404878] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/26/2014] [Indexed: 06/04/2023]
Abstract
CuInSe(x)S(2-x) quantum dot field-effect transistors show p-type, n-type, and ambipolar behaviors with carrier mobilities up to 0.03 cm(2) V(-1) s(-1). Although some design rules from studies of cadmium and lead containing quantum dots can be applied, remarkable differences are observed including a strong gating effect in as-synthesized nanocyrstals with long ligands.
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Affiliation(s)
- Sergiu Draguta
- Center for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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33
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ten Cate S, Sandeep CSS, Liu Y, Law M, Kinge S, Houtepen AJ, Schins JM, Siebbeles LDA. Generating free charges by carrier multiplication in quantum dots for highly efficient photovoltaics. Acc Chem Res 2015; 48:174-81. [PMID: 25607377 DOI: 10.1021/ar500248g] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CONSPECTUS: In a conventional photovoltaic device (solar cell or photodiode) photons are absorbed in a bulk semiconductor layer, leading to excitation of an electron from a valence band to a conduction band. Directly after photoexcitation, the hole in the valence band and the electron in the conduction band have excess energy given by the difference between the photon energy and the semiconductor band gap. In a bulk semiconductor, the initially hot charges rapidly lose their excess energy as heat. This heat loss is the main reason that the theoretical efficiency of a conventional solar cell is limited to the Shockley-Queisser limit of ∼33%. The efficiency of a photovoltaic device can be increased if the excess energy is utilized to excite additional electrons across the band gap. A sufficiently hot charge can produce an electron-hole pair by Coulomb scattering on a valence electron. This process of carrier multiplication (CM) leads to formation of two or more electron-hole pairs for the absorption of one photon. In bulk semiconductors such as silicon, the energetic threshold for CM is too high to be of practical use. However, CM in nanometer sized semiconductor quantum dots (QDs) offers prospects for exploitation in photovoltaics. CM leads to formation of two or more electron-hole pairs that are initially in close proximity. For photovoltaic applications, these charges must escape from recombination. This Account outlines our recent progress in the generation of free mobile charges that result from CM in QDs. Studies of charge carrier photogeneration and mobility were carried out using (ultrafast) time-resolved laser techniques with optical or ac conductivity detection. We found that charges can be extracted from photoexcited PbS QDs by bringing them into contact with organic electron and hole accepting materials. However, charge localization on the QD produces a strong Coulomb attraction to its counter charge in the organic material. This limits the production of free charges that can contribute to the photocurrent in a device. We show that free mobile charges can be efficiently produced via CM in solids of strongly coupled PbSe QDs. Strong electronic coupling between the QDs resulted in a charge carrier mobility of the order of 1 cm(2) V(-1) s(-1). This mobility is sufficiently high so that virtually all electron-hole pairs escape from recombination. The impact of temperature on the CM efficiency in PbSe QD solids was also studied. We inferred that temperature has no observable effect on the rate of cooling of hot charges nor on the CM rate. We conclude that exploitation of CM requires that charges have sufficiently high mobility to escape from recombination. The contribution of CM to the efficiency of photovoltaic devices can be further enhanced by an increase of the CM efficiency above the energetic threshold of twice the band gap. For large-scale applications in photovoltaic devices, it is important to develop abundant and nontoxic materials that exhibit efficient CM.
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Affiliation(s)
- Sybren ten Cate
- Optoelectronic Materials Section, Department of Chemical
Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | - C. S. Suchand Sandeep
- Optoelectronic Materials Section, Department of Chemical
Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | - Yao Liu
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Matt Law
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Sachin Kinge
- Toyota Motor Europe, Functional Nanomaterials Lab, Advanced Technology, Hoge Wei 33, B-1930 Zaventem, Belgium
| | - Arjan J. Houtepen
- Optoelectronic Materials Section, Department of Chemical
Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | - Juleon M. Schins
- Optoelectronic Materials Section, Department of Chemical
Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | - Laurens D. A. Siebbeles
- Optoelectronic Materials Section, Department of Chemical
Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
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34
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Zhang X, Liu J, Johansson EMJ. Efficient charge-carrier extraction from Ag₂S quantum dots prepared by the SILAR method for utilization of multiple exciton generation. NANOSCALE 2015; 7:1454-1462. [PMID: 25504257 DOI: 10.1039/c4nr04463k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The utilization of electron-hole pairs (EHPs) generated from multiple excitons in quantum dots (QDs) is of great interest toward efficient photovoltaic devices and other optoelectronic devices; however, extraction of charge carriers remains difficult. Herein, we extract photocharges from Ag2S QDs and investigate the dependence of the electric field on the extraction of charges from multiple exciton generation (MEG). Low toxic Ag2S QDs are directly grown on TiO2 mesoporous substrates by employing the successive ionic layer adsorption and reaction (SILAR) method. The contact between QDs is important for the initial charge separation after MEG and for the carrier transport, and the space between neighbor QDs decreases with more SILAR cycles, resulting in better charge extraction. At the optimal electric field for extraction of photocharges, the results suggest that the threshold energy (hνth) for MEG is 2.41Eg. The results reveal that Ag2S QD is a promising material for efficient extraction of charges from MEG and that QDs prepared by SILAR have an advantageous electrical contact facilitating charge separation and extraction.
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Affiliation(s)
- Xiaoliang Zhang
- Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden.
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35
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Hines DA, Forrest RP, Corcelli SA, Kamat PV. Predicting the Rate Constant of Electron Tunneling Reactions at the CdSe–TiO2 Interface. J Phys Chem B 2015; 119:7439-46. [DOI: 10.1021/jp5111295] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Douglas A. Hines
- Notre Dame Radiation Laboratory and ‡Department of
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Ryan P. Forrest
- Notre Dame Radiation Laboratory and ‡Department of
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Steven A. Corcelli
- Notre Dame Radiation Laboratory and ‡Department of
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Prashant V. Kamat
- Notre Dame Radiation Laboratory and ‡Department of
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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36
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Dalui A, Khan AH, Pradhan B, Pradhan J, Satpati B, Acharya S. Facile synthesis of composition and morphology modulated quaternary CuZnFeS colloidal nanocrystals for photovoltaic application. RSC Adv 2015. [DOI: 10.1039/c5ra18157g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Quaternary semiconductor CuZnFeS nanocrystals with controlled size, shape and composition have been successfully synthesized and utilized to fabricate photovoltaic and photosensitive devices.
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Affiliation(s)
- Amit Dalui
- Centre for Advanced Materials
- Indian Association for the Cultivation of Science
- Kolkata 700032
- India
| | - Ali Hossain Khan
- Centre for Advanced Materials
- Indian Association for the Cultivation of Science
- Kolkata 700032
- India
| | - Bapi Pradhan
- Centre for Advanced Materials
- Indian Association for the Cultivation of Science
- Kolkata 700032
- India
| | - Jayita Pradhan
- Centre for Advanced Materials
- Indian Association for the Cultivation of Science
- Kolkata 700032
- India
| | - Biswarup Satpati
- Surface Physics and Material Science Division
- Saha Institute of Nuclear Physics
- Kolkata 700064
- India
| | - Somobrata Acharya
- Centre for Advanced Materials
- Indian Association for the Cultivation of Science
- Kolkata 700032
- India
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37
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Huang J, Xu B, Yuan C, Chen H, Sun J, Sun L, Agren H. Improved performance of colloidal CdSe quantum dot-sensitized solar cells by hybrid passivation. ACS APPLIED MATERIALS & INTERFACES 2014; 6:18808-18815. [PMID: 25310596 DOI: 10.1021/am504536a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A hybrid passivation strategy is employed to modify the surface of colloidal CdSe quantum dots (QDs) for quantum dot-sensitized solar cells (QDSCs), by using mercaptopropionic acid (MPA) and iodide anions through a ligand exchange reaction in solution. This is found to be an effective way to improve the performance of QDSCs based on colloidal QDs. The results show that MPA can increase the coverage of the QDs on TiO2 electrodes and facilitate the hole extraction from the photoxidized QDs, and simultaneously, that the iodide anions can remedy the surface defects of the CdSe QDs and thus reduce the recombination loss in the device. This hybrid passivation treatment leads to a significant enhancement of the power conversion efficiency of the QDSCs by 41%. Furthermore, an optimal ratio of iodide ions to MPA was determined for favorable hybrid passivation; results show that excessive iodine anions are detrimental to the loading of the QDs. This study demonstrates that the improvement in QDSC performance can be realized by using a combination of different functional ligands to passivate the QDs, and that ligand exchange in solution can be an effective approach to introduce different ligands.
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Affiliation(s)
- Jing Huang
- Department of Theoretical Chemistry & Biology, School of Biotechnology, Royal Institute of Technology (KTH) , 106 91 Stockholm, Sweden
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38
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Kern ME, Watson DF. Linker-assisted attachment of CdSe quantum dots to TiO2: Time- and concentration-dependent adsorption, agglomeration, and sensitized photocurrent. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:13293-13300. [PMID: 25333329 DOI: 10.1021/la503211k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have characterized the concentration and time dependences of the attachment of colloidal CdSe quantum dots (QDs) to 16-mercaptohexadanoic acid (MHDA)-functionalized nanocrystalline TiO2 thin films. The amount of QDs and the extent of their agglomeration on MHDA-functionalized TiO2 films were characterized by transmission- and reflectance-mode UV/vis absorption spectroscopy and scanning electron microscopy. Optically transparent films with spatially homogeneous coloration and minimal agglomeration of QDs were prepared from 2.2 and 5.0 μM toluene dispersions of QDs at short reaction times (<5 h). In contrast, prolonged exposure of MHDA-functionalized TiO2 films to 22 μM dispersions of QDs yielded relatively opaque QD-functionalized films with spatially inhomogeneous coloration and substantial agglomeration of QDs. Agglomeration of QDs decreased the absorbed photon-to-current efficiencies of QD-sensitized solar cells (QDSSCs) by almost 3-fold. These results highlight the profound influence of agglomeration on the optical properties and interfacial electron-transfer reactivity of QD-functionalized TiO2 films prepared by in situ linker-assisted assembly as well as the photoelectrochemical performance of QDSSCs incorporating such films.
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Affiliation(s)
- Meghan E Kern
- Department of Chemistry, University at Buffalo, The State University of New York , Buffalo, New York 14260-3000, United States
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39
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Stolle CJ, Schaller RD, Korgel BA. Efficient Carrier Multiplication in Colloidal CuInSe2 Nanocrystals. J Phys Chem Lett 2014; 5:3169-74. [PMID: 26276328 DOI: 10.1021/jz501640f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Transient absorption spectroscopy (TAS) was used to study carrier multiplication (CM) (also called multiexciton generation (MEG)) in solvent-dispersed colloidal CuInSe2 nanocrystals with diameters as small as 4.5 nm. Size-dependent carrier cooling rates, absorption cross sections, and Auger lifetimes were also determined. The energy threshold for CM in the CuInSe2 nanocrystals was found to be 2.4 ± 0.2 times the nanocrystal energy gap (Eg) and the CM efficiency was 36 ± 6% per unit Eg. This is similar to other types of nanocrystal quantum dot materials.
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Affiliation(s)
- C Jackson Stolle
- †McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Richard D Schaller
- ‡Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- §Center for Nanoscale Materials, Argonne National Laboratories, Argonne, Illinois 60439, United States
| | - Brian A Korgel
- †McKetta Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, United States
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40
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Tao X, Mafi E, Gu Y. Synthesis and Ultrafast Carrier Dynamics of Single-Crystal Two-Dimensional CuInSe2 Nanosheets. J Phys Chem Lett 2014; 5:2857-2862. [PMID: 26278089 DOI: 10.1021/jz501242m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report, for the first time, the synthesis of single-crystal two-dimensional (2D) CuInSe2 nanosheets and the studies of ultrafast carrier dynamics and transport in this 2D material. Particularly, single-crystal 2D CuInSe2 with various thicknesses in the nanometer regime were fabricated by a solid-state chemical reaction between Cu and single-crystal exfoliated In2Se3 nanosheets. Characteristics of transient optical reflectivity, obtained from femtosecond optical pump-probe measurements on single CuInSe2 nanosheets, suggest that the hot carrier cooling process dominates the carrier dynamics within a few picoseconds following the optical excitation. Spatially resolved pump-probe measurements, coupled to simple model calculations, were used to obtain the ambipolar hot carrier diffusion coefficient in single nanosheets. The dependence of the hot carrier diffusion coefficient on the nanosheet thickness provides insight into the limiting mechanisms of hot carrier transport and can be used to gauge the possibility of efficient hot carrier collection in nanostructured CuInSe2 solar cells.
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Affiliation(s)
- Xin Tao
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164, United States
| | - Elham Mafi
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164, United States
| | - Yi Gu
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164, United States
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41
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Kamat PV, Christians JA, Radich EJ. Quantum dot solar cells: hole transfer as a limiting factor in boosting the photoconversion efficiency. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5716-5725. [PMID: 24669885 DOI: 10.1021/la500555w] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Semiconductor nanostructures are attractive for designing low-cost solar cells with tunable photoresponse. The recent advances in size- and shape-selective synthesis have enabled the design of quantum dot solar cells with photoconversion efficiencies greater than 5%. To make them competitive with other existing thin film or polycrystalline photovoltaic technologies, it is important to overcome kinetic barriers for charge transfer at semiconductor interfaces. This feature article focuses on the limitations imposed by slow hole transfer in improving solar cell performance and its role in the stability of metal chalcogenide solar cells. Strategies to improve the rate of hole transfer through surface-modified redox relays offer new opportunities to overcome the hole-transfer limitation. The mechanistic and kinetic aspects of hole transfer in quantum dot solar cells (QDSCs), nanowire solar cells (NWSCs), and extremely thin absorber (ETA) solar cells are discussed.
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Affiliation(s)
- Prashant V Kamat
- Radiation Laboratory and Department of Chemical & Biomolecular Engineering, University of Notre Dame , Notre Dame, Indiana 46556, United States
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