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Chen B, Zheng W, Chun F, Xu X, Zhao Q, Wang F. Synthesis and hybridization of CuInS 2 nanocrystals for emerging applications. Chem Soc Rev 2023; 52:8374-8409. [PMID: 37947021 DOI: 10.1039/d3cs00611e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Copper indium sulfide (CuInS2) is a ternary A(I)B(III)X(VI)2-type semiconductor featuring a direct bandgap with a high absorption coefficient. In attempts to explore their practical applications, nanoscale CuInS2 has been synthesized with crystal sizes down to the quantum confinement regime. The merits of CuInS2 nanocrystals (NCs) include wide emission tunability, a large Stokes shift, long decay time, and eco-friendliness, making them promising candidates in photoelectronics and photovoltaics. Over the past two decades, advances in wet-chemistry synthesis have achieved rational control over cation-anion reactivity during the preparation of colloidal CuInS2 NCs and post-synthesis cation exchange. The precise nano-synthesis coupled with a series of hybridization strategies has given birth to a library of CuInS2 NCs with highly customizable photophysical properties. This review article focuses on the recent development of CuInS2 NCs enabled by advanced synthetic and hybridization techniques. We show that the state-of-the-art CuInS2 NCs play significant roles in optoelectronic and biomedical applications.
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Affiliation(s)
- Bing Chen
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, Jiangsu 210023, China.
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon 999077, Hong Kong SAR, China.
| | - Weilin Zheng
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon 999077, Hong Kong SAR, China.
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
| | - Fengjun Chun
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon 999077, Hong Kong SAR, China.
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
| | - Xiuwen Xu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, Jiangsu 210023, China.
| | - Qiang Zhao
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, Jiangsu 210023, China.
- State Key Laboratory of Organic Electronics and Information Displays, Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, Jiangsu 210023, China
| | - Feng Wang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon 999077, Hong Kong SAR, China.
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
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2
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Dehnel J, Harchol A, Barak Y, Meir I, Horani F, Shapiro A, Strassberg R, de Mello Donegá C, Demir HV, Gamelin DR, Sharma K, Lifshitz E. Optically detected magnetic resonance spectroscopic analyses on the role of magnetic ions in colloidal nanocrystals. J Chem Phys 2023; 159:071001. [PMID: 37581419 DOI: 10.1063/5.0160787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/26/2023] [Indexed: 08/16/2023] Open
Abstract
Incorporating magnetic ions into semiconductor nanocrystals has emerged as a prominent research field for manipulating spin-related properties. The magnetic ions within the host semiconductor experience spin-exchange interactions with photogenerated carriers and are often involved in the recombination routes, stimulating special magneto-optical effects. The current account presents a comparative study, emphasizing the impact of engineering nanostructures and selecting magnetic ions in shaping carrier-magnetic ion interactions. Various host materials, including the II-VI group, halide perovskites, and I-III-VI2 in diverse structural configurations such as core/shell quantum dots, seeded nanorods, and nanoplatelets, incorporated with magnetic ions such as Mn2+, Ni2+, and Cu1+/2+ are highlighted. These materials have recently been investigated by us using state-of-the-art steady-state and transient optically detected magnetic resonance (ODMR) spectroscopy to explore individual spin-dynamics between the photogenerated carriers and magnetic ions and their dependence on morphology, location, crystal composition, and type of the magnetic ion. The information extracted from the analyses of the ODMR spectra in those studies exposes fundamental physical parameters, such as g-factors, exchange coupling constants, and hyperfine interactions, together providing insights into the nature of the carrier (electron, hole, dopant), its local surroundings (isotropic/anisotropic), and spin dynamics. The findings illuminate the importance of ODMR spectroscopy in advancing our understanding of the role of magnetic ions in semiconductor nanocrystals and offer valuable knowledge for designing magnetic materials intended for various spin-related technologies.
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Affiliation(s)
- Joanna Dehnel
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Adi Harchol
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yahel Barak
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Itay Meir
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Faris Horani
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
| | - Arthur Shapiro
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Optical Materials Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Rotem Strassberg
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Celso de Mello Donegá
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Hilmi Volkan Demir
- Luminous Center of Excellence for Semiconductor Lighting and Displays, TPI, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, School of Materials Science and Engineering, Nanyang Technological University-NTU Singapore, 639798, Singapore
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Türkiye
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
| | - Kusha Sharma
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Efrat Lifshitz
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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3
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Al-Maskari S, Issac A, Varanasi SR, Hildner R, Sofin RGS, Ibrahim AR, Abou-Zied OK. Dye-induced photoluminescence quenching of quantum dots: role of excited state lifetime and confinement of charge carriers. Phys Chem Chem Phys 2023; 25:14126-14137. [PMID: 37161937 DOI: 10.1039/d3cp00715d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We investigate the role of quantum confinement and photoluminescence (PL) lifetime of photoexcited charge carriers in semiconductor core/shell quantum dots (QDs) via PL quenching due to surface modification. Surface modification is controlled by varying the number of dye molecules adsorbed onto the QD shell surface forming QD-dye nanoassemblies. We selected CuInS2/ZnS (CIS) and InP/ZnS (InP) core/shell QDs exhibiting relatively weak (664 meV) and strong (1194 meV) confinement potentials for the conduction band electron. Moreover, the difference in the emission mechanism gives rise to a long and short excited state lifetime of CIS (ca. 290 ns) and InP (ca. 37 ns) QDs. Dye molecules of different ionic characters (rhodamine 575: zwitterionic and rhodamine 560: cationic) are used as quenchers. A detailed analysis of Stern-Volmer data shows that (i) quenching is generally more pronounced in CIS-dye assemblies as compared to InP-dye assemblies, (ii) dynamic quenching is dominating in all QD-dye assemblies with only a minor contribution from static quenching and (iii) the cationic dye shows a stronger interaction with the QD shell surface than the zwitterionic dye. Observations (i) and (ii) can be explained by the differences in the amplitude of the electronic component of the exciton wavefunction near the dye binding sites in both QDs, which results in the breaking up of the electron-hole pair and favors charge trapping. Observation (iii) can be attributed to the variations in electrostatic interactions between the negatively charged QD shell surface and the cationic and zwitterionic dyes, with the former exhibiting a stronger interaction. Moreover, the long lifetime of CIS QDs facilitates us to easily probe different time scales of the trapping processes and thus differentiate the origins of static and dynamic quenching components that appear in the Stern-Volmer analysis.
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Affiliation(s)
- Saleem Al-Maskari
- Department of Physics, College of Science, Sultan Qaboos University, Muscat 123, Oman.
| | - Abey Issac
- Department of Physics, College of Science, Sultan Qaboos University, Muscat 123, Oman.
| | | | - Richard Hildner
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - R G Sumesh Sofin
- Department of Physics, College of Science, Sultan Qaboos University, Muscat 123, Oman.
| | - A Ramadan Ibrahim
- Department of Chemistry, College of Science, Sultan Qaboos University, Muscat 123, Oman
| | - Osama K Abou-Zied
- Department of Chemistry, College of Science, Sultan Qaboos University, Muscat 123, Oman
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4
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Harchol A, Barak Y, Hughes KE, Hartstein KH, Jöbsis HJ, Prins PT, de Mello Donegá C, Gamelin DR, Lifshitz E. Optically Detected Magnetic Resonance Spectroscopy of Cu-Doped CdSe/CdS and CuInS 2 Colloidal Quantum Dots. ACS NANO 2022; 16:12866-12877. [PMID: 35913892 DOI: 10.1021/acsnano.2c05130] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Copper-doped II-VI and copper-based I-III-VI2 colloidal quantum dots (CQDs) have been at the forefront of interest in nanocrystals over the past decade, attributable to their optically activated copper states. However, the related recombination mechanisms are still unclear. The current work elaborates on recombination processes in such materials by following the spin properties of copper-doped CdSe/CdS (Cu@CdSe/CdS) and of CuInS2 and CuInS2/(CdS, ZnS) core/shell CQDs using continuous-wave and time-resolved optically detected magnetic resonance (ODMR) spectroscopy. The Cu@CdSe/CdS ODMR showed two distinct resonances with different g factors and spin relaxation times. The best fit by a spin Hamiltonian simulation suggests that emission comes from recombination of a delocalized electron at the conduction band edge with a hole trapped in a Cu2+ site with a weak exchange coupling between the two spins. The ODMR spectra of CuInS2 CQDs (with and without shells) differ significantly from those of the copper-doped II-VI CQDs. They are comprised of a primary resonance accompanied by another resonance at half-field, with a strong correlation between the two, indicating the involvement of a triplet exciton and hence stronger electron-hole exchange coupling than in the doped core/shell CQDs. The spin Hamiltonian simulation shows that the hole is again associated with a photogenerated Cu2+ site. The electron resides near this Cu2+ site, and its ODMR spectrum shows contributions from superhyperfine coupling to neighboring indium atoms. These observations are consistent with the occurrence of a self-trapped exciton associated with the copper site. The results presented here support models under debate for over a decade and help define the magneto-optical properties of these important materials.
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Affiliation(s)
- Adi Harchol
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yahel Barak
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Kira E Hughes
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Kimberly H Hartstein
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Huygen J Jöbsis
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - P Tim Prins
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Celso de Mello Donegá
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Efrat Lifshitz
- Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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5
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Harvey SM, Houck DW, Liu W, Liu Y, Gosztola DJ, Korgel BA, Wasielewski MR, Schaller RD. Synthetic Ligand Selection Affects Stoichiometry, Carrier Dynamics, and Trapping in CuInSe 2 Nanocrystals. ACS NANO 2021; 15:19588-19599. [PMID: 34806353 DOI: 10.1021/acsnano.1c06625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
CuInSe2 nanocrystals exhibit tunable near-infrared bandgaps that bolster utility in photovoltaic applications as well as offer potential as substitutes for more toxic Cd- and Pb-based semiconductor compositions. However, they can present a variety of defect states and unusual photophysics. Here, we examine the effects of ligand composition (oleylamine, diphenylphosphine, and tributylphosphine) on carrier dynamics in these materials. Via spectroscopic measurements such as photoluminescence and transient absorption, we find that ligands present during the synthesis of CuInSe2 nanocrystals impart nonradiative electronic states which compete with radiative recombination and give rise to low photoluminescence quantum yields. We characterize the nature of these defect states (hole vs electron traps) and investigate whether they exist at the surface or interior of the nanocrystals. Carrier lifetimes are highly dependent on ligand identity where oleylamine-capped nanocrystals exhibit rapid trapping (<20 ps) followed by diphenylphosphine (<500 ps) and finally tributylphosphine (>2 ns). A majority of carrier population localizes at indium copper antisites (electrons), copper vacancies (holes), or surface traps (electrons and/or holes), all of which are nonemissive.
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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
| | - Wen Liu
- McKetta Department of Chemical Engineering, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yuzi Liu
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - David J Gosztola
- Center for Nanoscale Materials, 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
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
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6
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Iida K, Uehigashi Y, Kim D. Origin of photoluminescence of water-soluble CuInS 2 quantum dots prepared via a hydrothermal method. RSC Adv 2021; 11:33186-33191. [PMID: 35497559 PMCID: PMC9042224 DOI: 10.1039/d1ra05761h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/01/2021] [Indexed: 11/21/2022] Open
Abstract
This study was performed to investigate the origin of the photoluminescence (PL) properties of hydrothermally-synthesized water-soluble CuInS2 (CIS) quantum dots (QDs). The corresponding PL decay profiles, time-resolved PL spectra, and excitation intensity dependence of the PL spectra were evaluated. The decay profiles exhibited a strong dependence on the detection energy, and the peak of the time-resolved PL spectra shifted to lower energies with increasing time. With increasing excitation light intensity, the PL peak shifted to the high-energy side. These experimental results were consistent with the characteristics of donor–acceptor pair emission. The PL properties of Cu-doped and non-doped CdSe QDs, which show Cu-related and defect-related PL emission, respectively, were compared. Based on these results, it was concluded that donor–acceptor pair emission is the underlying mechanism of the PL of the hydrothermally-synthesized water-soluble CIS QDs. The donor–acceptor pair emission is the underlying mechanism of the PL of the hydrothermally-synthesized water-soluble CIS QDs.![]()
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Affiliation(s)
- Kazutaka Iida
- Department of Applied Physics, Graduate School of Engineering, Osaka City University 3-3-138, Sugimoto, Sumiyoshi-ku Osaka 558-8585 Japan
| | - Yota Uehigashi
- Department of Applied Physics, Graduate School of Engineering, Osaka City University 3-3-138, Sugimoto, Sumiyoshi-ku Osaka 558-8585 Japan
| | - DaeGwi Kim
- Department of Applied Physics, Graduate School of Engineering, Osaka City University 3-3-138, Sugimoto, Sumiyoshi-ku Osaka 558-8585 Japan
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7
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Lorenz S, Bieniek J, Erickson CS, Gamelin DR, Fainblat R, Bacher G. Orientation of Individual Anisotropic Nanocrystals Identified by Polarization Fingerprint. ACS NANO 2021; 15:13579-13590. [PMID: 34339182 DOI: 10.1021/acsnano.1c04451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The polarization of photoluminescence emitted from anisotropic nanocrystals directly reflects the symmetry of the eigenstates involved in the recombination process and can thus be considered as a characteristic feature of a nanocrystal. We performed polarization resolved magneto-photoluminescence spectroscopy on single colloidal Mn2+:CdSe/CdS core-shell quantum dots of wurtzite crystal symmetry. At zero magnetic field, a distinct linear polarization pattern is observed, while applying a magnetic field enforces circularly polarized emission with a characteristic saturation value below 100%. These polarization features are shown to act as a specific fingerprint of each individual nanocrystal. A model considering the orientation of the crystal c⃗ axis with respect to the optical axis and the magnetic field and taking into account the impact of magnetic doping is introduced and quantitatively explains our findings. We demonstrate that a careful analysis of the polarization state of single nanocrystal emission using the full set of Stokes parameters allows for identification of the complete three-dimensional orientation of the crystal anisotropy axis of an individual nanoobject in lab coordinates.
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Affiliation(s)
- Severin Lorenz
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - Jan Bieniek
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - Christian S Erickson
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Rachel Fainblat
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - Gerd Bacher
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
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8
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Tsolekile N, Nahle S, Zikalala N, Parani S, Sakho EHM, Joubert O, Matoetoe MC, Songca SP, Oluwafemi OS. Cytotoxicity, fluorescence tagging and gene-expression study of CuInS/ZnS QDS - meso (hydroxyphenyl) porphyrin conjugate against human monocytic leukemia cells. Sci Rep 2020; 10:4936. [PMID: 32188925 PMCID: PMC7080734 DOI: 10.1038/s41598-020-61881-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 03/03/2020] [Indexed: 12/11/2022] Open
Abstract
The toxicity of heavy metals present in binary semiconductor nanoparticles also known as quantum dots (QDs) has hindered their wide applications hence the advent of non-toxic ternary quantum dots. These new group of quantum dots have been shown to possess some therapeutic action against cancer cell lines but not significant enough to be referred to as an ideal therapeutic agent. In this report, we address this problem by conjugating red emitting CuInS/ZnS QDs to a 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin -photosensitizer for improved bioactivities. The glutathione capped CuInS/ZnS QDs were synthesized in an aqueous medium using a kitchen pressure cooker at different Cu: In ratios (1:4 and 1:8) and at varied temperatures (95 °C, 190 °C and 235 °C). Optical properties show that the as-synthesized CuInS/ZnS QDs become red-shifted compared to the core (CuInS) after passivation with emission in the red region while the cytotoxicity study revealed excellent cell viability against normal kidney fibroblasts (BHK21). The highly fluorescent, water-soluble QDs were conjugated to 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (mTHPP) via esterification reactions at room temperature. The resultant water-soluble conjugate was then used for the cytotoxicity, fluorescent imaging and gene expression study against human monocytic leukemia cells (THP-1). Our result showed that the conjugate possessed high cytotoxicity against THP-1 cells with enhanced localized cell uptake compared to the bare QDs. In addition, the gene expression study revealed that the conjugate induced inflammation compared to the QDs as NFKB gene was over-expressed upon cell inflammation while the singlet oxygen (1O2) study showed the conjugate possessed large amount of 1O2, three times than the bare porphyrin. Thus, the as-synthesized conjugate looks promising as a therapeutic agent for cancer therapy.
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Affiliation(s)
- Ncediwe Tsolekile
- Department of Chemical Sciences, University of Johannesburg, P. O. Box 17011, Doornfontein, 2028, Johannesburg, South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg, South Africa
- Department of Chemistry, Cape Peninsula University of Technology, P.O. Box 652, Cape Town, 2000, South Africa
| | - Sara Nahle
- Université De Lorraine, Faculté de Pharmacie, F-54001, Nancy Cedex, France
| | - Nkosingiphile Zikalala
- Department of Chemical Sciences, University of Johannesburg, P. O. Box 17011, Doornfontein, 2028, Johannesburg, South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg, South Africa
| | - Sundararajan Parani
- Department of Chemical Sciences, University of Johannesburg, P. O. Box 17011, Doornfontein, 2028, Johannesburg, South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg, South Africa
| | - El Hadji Mamour Sakho
- Department of Chemical Sciences, University of Johannesburg, P. O. Box 17011, Doornfontein, 2028, Johannesburg, South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg, South Africa
| | - Olivier Joubert
- Université De Lorraine, Faculté de Pharmacie, F-54001, Nancy Cedex, France
| | - Mangaka C Matoetoe
- Department of Chemistry, Cape Peninsula University of Technology, P.O. Box 652, Cape Town, 2000, South Africa
| | - Sandile P Songca
- Department of Chemistry, University of KwaZulu-Natal, Private Bag X 54001, Durban, 4000, South Africa
| | - Oluwatobi S Oluwafemi
- Department of Chemical Sciences, University of Johannesburg, P. O. Box 17011, Doornfontein, 2028, Johannesburg, South Africa.
- Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg, South Africa.
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9
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Fuhr A, Yun HJ, Crooker SA, Klimov VI. Spectroscopic and Magneto-Optical Signatures of Cu 1+ and Cu 2+ Defects in Copper Indium Sulfide Quantum Dots. ACS NANO 2020; 14:2212-2223. [PMID: 31927981 DOI: 10.1021/acsnano.9b09181] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Colloidal quantum dots (QDs) of I-III-VI ternary compounds such as copper indium sulfide (CIS) and copper indium selenide (CISe) have been under intense investigation due to both their unusual photophysical properties and considerable technological utility. These materials feature a toxic-element-free composition, a tunable bandgap that covers near-infrared and visible spectral energies, and a highly efficient photoluminescence (PL) whose spectrum is located in the reabsorption-free intragap region. These properties make them attractive for light-emission and light-harvesting applications including photovoltaics and luminescent solar concentrators. Despite a large body of literature on device-related studies of CISe(S) QDs, the understanding of their fundamental photophysical properties is surprisingly poor. Two particular subjects that are still heavily debated in the literature include the mechanism(s) for strong intragap emission and the reason(s) for a poorly defined (featureless) absorption edge, which often "tails" below the nominal bandgap. Here, we address these questions by conducting comprehensive spectroscopic studies of CIS QD samples with varied Cu-to-In ratios using resonant PL and PL excitation, femtosecond transient absorption, and magnetic circular dichroism measurements. These studies reveal a strong effect of stoichiometry on the concentration of Cu1+ vs Cu2+ defects (occurring as CuIn″ and CuCu• species, respectively), and their effects on QD optical properties. In particular, we demonstrate that the increase in the relative amount of Cu2+ vs Cu1+ centers suppresses intragap absorption associated with Cu1+ states and sharpens band-edge absorption. In addition, we show that both Cu1+ and Cu2+ centers are emissive but are characterized by distinct activation mechanisms and slightly different emission energies due to different crystal lattice environments. An important overall conclusion of this study is that the relative importance of the Cu2+ vs Cu1+ emission/absorption channels can be controlled by tuning the Cu-to-In ratio, suggesting that the control of sample stoichiometry represents a powerful tool for achieving functionalities (e.g., strong intragap emission) that are not accessible with ideal, defect-free materials.
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Affiliation(s)
- Addis Fuhr
- Chemistry Division, C-PCS , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
- Department of Chemical and Biomolecular Engineering , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Hyeong Jin Yun
- Chemistry Division, C-PCS , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Scott A Crooker
- National High Magnetic Field Laboratory , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Victor I Klimov
- Chemistry Division, C-PCS , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
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10
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Hansen EC, Liu Y, Utzat H, Bertram SN, Grossman JC, Bawendi MG. Blue Light Emitting Defective Nanocrystals Composed of Earth-Abundant Elements. Angew Chem Int Ed Engl 2019; 59:860-867. [PMID: 31693785 DOI: 10.1002/anie.201911436] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/17/2019] [Indexed: 11/09/2022]
Abstract
Copper-based ternary (I-III-VI) chalcogenide nanocrystals (NCs) are compositionally-flexible semiconductors that do not contain lead (Pb) or cadmium (Cd). Cu-In-S NCs are the dominantly studied member of this important materials class and have been reported to contain optically-active defect states. However, there are minimal reports of In-free compositions that exhibit efficient photoluminescence (PL). Here, we report a novel solution-phase synthesis of ≈4 nm defective nanocrystals (DNCs) composed of copper, aluminum, zinc, and sulfur with ≈20 % quantum yield and an attractive PL maximum of 450 nm. Extensive spectroscopic characterization suggests the presence of highly localized electronic states resulting in reasonably fast PL decays (≈1 ns), large vibrational energy spacing, small Stokes shift, and temperature-independent PL linewidth and PL lifetime (between room temperature and ≈5 K). Furthermore, density functional theory (DFT) calculations suggest PL transitions arise from defects within a CuAl5 S8 crystal lattice, which supports the experimental observation of highly-localized states. The results reported here provide a new material with unique optoelectronic characteristics that is an important analog to well-explored Cu-In-S NCs.
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Affiliation(s)
- Eric C Hansen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Yun Liu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Hendrik Utzat
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Sophie N Bertram
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Moungi G Bawendi
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
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11
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Hansen EC, Liu Y, Utzat H, Bertram SN, Grossman JC, Bawendi MG. Blue Light Emitting Defective Nanocrystals Composed of Earth‐Abundant Elements. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911436] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Eric C. Hansen
- Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Yun Liu
- Department of Materials Science and Engineering Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Hendrik Utzat
- Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Sophie N. Bertram
- Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Jeffrey C. Grossman
- Department of Materials Science and Engineering Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Moungi G. Bawendi
- Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
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12
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Gromova Y, Sokolova A, Kurshanov D, Korsakov I, Osipova V, Cherevkov S, Dubavik A, Maslov V, Perova T, Gun'ko Y, Baranov A, Fedorov A. Investigation of AgInS 2/ZnS Quantum Dots by Magnetic Circular Dichroism Spectroscopy. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3616. [PMID: 31689939 PMCID: PMC6862164 DOI: 10.3390/ma12213616] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 12/16/2022]
Abstract
Over recent years, quantum dots (QDs) based on ternary metal dichalcogenides have attracted a lot of attention due to their unique properties and a range of potential applications. Here, we review the latest studies on the optical properties of AgInS2/ZnS QDs with emphasis on their theoretical modeling, and present our investigations of electronic transitions invisible in unstructured absorption spectra of AgInS2/ZnS QDs. The analysis of the absorption, photoluminescence excitation (PLE), and magnetic circular dichroism (MCD) spectra of hydrophobic and hydrophilic AgInS2/ZnS QDs of different sizes enables us to determine positions of electron transitions in these QDs. We demonstrate that the use of the second derivative of PLE spectra provides more unequivocal data on the position of the energy transitions compared with the second derivative of absorption spectra. Analysis of the MCD spectra reveals that the magnetic field induces energy level mixing in AgInS2/ZnS QDs in contrast to the traditional Cd-based QDs, where MCD is associated only with removing degeneracy of the excited energy level.
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Affiliation(s)
- Yulia Gromova
- School of Chemistry, Trinity College, University of Dublin, Dublin 2, Dublin, Ireland.
| | - Anastasiia Sokolova
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Danil Kurshanov
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Ivan Korsakov
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Victoria Osipova
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Sergei Cherevkov
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Aliaksei Dubavik
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Vladimir Maslov
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Tatiana Perova
- School of Chemistry, Trinity College, University of Dublin, Dublin 2, Dublin, Ireland.
| | - Yurii Gun'ko
- School of Chemistry, Trinity College, University of Dublin, Dublin 2, Dublin, Ireland.
| | - Alexander Baranov
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
| | - Anatoly Fedorov
- Center of informational optical technologies ITMO University, St. Petersburg 197101, Russia.
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13
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Yang L, Antanovich A, Prudnikau A, Taniya OS, Grzhegorzhevskii KV, Zelenovskiy P, Terpinskaya T, Tang J, Artemyev M. Highly luminescent Zn-Cu-In-S/ZnS core/gradient shell quantum dots prepared from indium sulfide by cation exchange for cell labeling and polymer composites. NANOTECHNOLOGY 2019; 30:395603. [PMID: 31212270 DOI: 10.1088/1361-6528/ab2aa2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Gradient core-shell Zn-Cu-In-S/ZnS quantum dots (QDs) of small size and with highly efficient photoluminescence were synthesized via a multi-step high-temperature method involving cation exchange. The procedure starts with the preparation of indium sulfide nanoparticles followed by the addition of Cu and Zn precursors. At this stage, Zn replaces Cu atoms and as a result the concentration of Cu ions in the final QDs is only about 5% of the total In content in a QD. Zn incorporation and the formation of a gradient ZnS shell dramatically increases the photoluminescence quantum yield. Furthermore, the formation of the ZnS shell improves the chemical stability of Cu-In-S QDs, as demonstrated by the preparation of polystyrene-QD composites and labeling of glioma cells. This work provides an effective strategy for obtaining efficient and stable fluorophores free of heavy metals.
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Affiliation(s)
- Lanlan Yang
- Institute of Hybrid Materials, National Center of International Joint Research for Hybrid Materials Technology, National Base of International Sci. & Tech. Cooperation on Hybrid Materials, Qingdao University, 308 Ningxia Road, Qingdao 266071, People's Republic of China
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14
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Berends AC, Mangnus MJJ, Xia C, Rabouw FT, de Mello Donega C. Optoelectronic Properties of Ternary I-III-VI 2 Semiconductor Nanocrystals: Bright Prospects with Elusive Origins. J Phys Chem Lett 2019; 10:1600-1616. [PMID: 30883139 PMCID: PMC6452418 DOI: 10.1021/acs.jpclett.8b03653] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Colloidal nanocrystals of ternary I-III-VI2 semiconductors are emerging as promising alternatives to Cd- and Pb-chalcogenide nanocrystals because of their inherently lower toxicity, while still offering widely tunable photoluminescence. These properties make them promising materials for a variety of applications. However, the realization of their full potential has been hindered by both their underdeveloped synthesis and the poor understanding of their optoelectronic properties, whose origins are still under intense debate. In this Perspective, we provide novel insights on the latter aspect by critically discussing the accumulated body of knowledge on I-III-VI2 nanocrystals. From our analysis, we conclude that the luminescence in these nanomaterials most likely originates from the radiative recombination of a delocalized conduction band electron with a hole localized at the group-I cation, which results in broad bandwidths, large Stokes shifts, and long exciton lifetimes. Finally, we highlight the remaining open questions and propose experiments to address them.
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15
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Review of Core/Shell Quantum Dots Technology Integrated into Building’s Glazing. ENERGIES 2019. [DOI: 10.3390/en12061058] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Skylights and windows are building openings that enhance human comfort and well-being in various ways. Recently, a massive drive is witnessed to replace traditional openings with building integrated photovoltaic (BIPV) systems to generate power in a bid to reduce buildings’ energy. The problem with most of the BIPV glazing lies in the obstruction of occupants’ vision of the outdoor view. In order to resolve this problem, new technology has emerged that utilizes quantum dots semiconductors (QDs) in glazing systems. QDs can absorb and re-emit the incoming radiation in the desired direction with the tunable spectrum, which renders them favorable for building integration. By redirecting the radiation towards edges of the glazing, they can be categorized as luminescent solar concentrators (QD-LSCs) that can help to generate electricity while maintaining transparency in the glazing. The aim of this paper is to review the different properties of core/shell quantum dots and their potential applications in buildings. Literature from various disciplines was reviewed to establish correlations between the optical and electrical properties of different types, sizes, thicknesses, and concentration ratios of QDs when used in transparent glazing. The current article will help building designers and system integrators assess the merits of integrating QDs on windows/skylights with regards to energy production and potential impact on admitted daylighting and visual comfort.
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16
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Hughes KE, Ostheller SR, Nelson HD, Gamelin DR. Copper's Role in the Photoluminescence of Ag 1- xCu xInS 2 Nanocrystals, from Copper-Doped AgInS 2 ( x ∼ 0) to CuInS 2 ( x = 1). NANO LETTERS 2019; 19:1318-1325. [PMID: 30584807 DOI: 10.1021/acs.nanolett.8b04905] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A series of Ag1- xCu xInS2 nanocrystals (NCs) spanning from 0 ≤ x ≤ ∼1 was synthesized by partial cation exchange to identify copper's contributions to the electronic structure and spectroscopic properties of these NCs. Discrete midgap states appear above the valence band upon doping AgInS2 NCs with Cu+ (small x). Density functional theory calculations confirm that these midgap states are associated with the 3d valence orbitals of the Cu+ impurities. With increasing x, these impurity d levels gradually evolve to become the valence-band edge of CuInS2 NCs, but the highest-occupied orbital's description does not change significantly across the entire range of x. In contrast with this gradual evolution, Ag1- xCu xInS2 NC photoluminescence shifts rapidly with initial additions of Cu+ (small x) but then becomes independent of x beyond x > ∼0.20, all the way to CuInS2 ( x = 1.00). Data analysis suggests small but detectable hole delocalization in the luminescent excited state of CuInS2 NCs, estimated by Monte Carlo simulations to involve at most about four copper ions. These results provide unique insights into the luminescent excited states of these materials and they reinforce the description of CuInS2 NCs as "heavily copper-doped NCs" in which photogenerated holes are rapidly localized in copper 3d-based orbitals.
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Affiliation(s)
- Kira E Hughes
- Department of Chemistry , University of Washington , Seattle , Washington 98195-1700 , United States
| | - Sarah R Ostheller
- Department of Chemistry , University of Washington , Seattle , Washington 98195-1700 , United States
| | - Heidi D Nelson
- Department of Chemistry , University of Washington , Seattle , Washington 98195-1700 , United States
| | - Daniel R Gamelin
- Department of Chemistry , University of Washington , Seattle , Washington 98195-1700 , United States
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17
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2D/2D Z-scheme heterojunction of CuInS2/g-C3N4 for enhanced visible-light-driven photocatalytic activity towards the degradation of tetracycline. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.08.055] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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18
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van der Stam W, de Graaf M, Gudjonsdottir S, Geuchies JJ, Dijkema JJ, Kirkwood N, Evers WH, Longo A, Houtepen AJ. Tuning and Probing the Distribution of Cu + and Cu 2+ Trap States Responsible for Broad-Band Photoluminescence in CuInS 2 Nanocrystals. ACS NANO 2018; 12:11244-11253. [PMID: 30372029 PMCID: PMC6262458 DOI: 10.1021/acsnano.8b05843] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The processes that govern radiative recombination in ternary CuInS2 (CIS) nanocrystals (NCs) have been heavily debated, but recently, several research groups have come to the same conclusion that a photoexcited electron recombines with a localized hole on a Cu-related trap state. Furthermore, it has been observed that single CIS NCs display narrower photoluminescence (PL) line widths than the ensemble, which led to the conclusion that within the ensemble there is a distribution of Cu-related trap states responsible for PL. In this work, we probe this trap-state distribution with in situ photoluminescence spectroelectrochemistry. We find that Cu2+ states result in individual "dark" nanocrystals, whereas Cu+ states result in "bright" NCs. Furthermore, we show that we can tune the PL position, intensity, and line width in a cyclic fashion by injecting or removing electrons from the trap-state distribution, thereby converting a subset of "dark" Cu2+ containing NCs into "bright" Cu+ containing NCs and vice versa. The electrochemical injection of electrons results in brightening, broadening, and a red shift of the PL, in line with the activation of a broad distribution of "dark" NCs (Cu2+ states) into "bright" NCs (Cu+ states) and a rise of the Fermi level within the ensemble trap-state distribution. The opposite trend is observed for electrochemical oxidation of Cu+ states into Cu2+. Our work shows that there is a direct correlation between the line width of the ensemble Cu+/Cu2+ trap-state distribution and the characteristic broad-band PL feature of CIS NCs and between Cu2+ cations in the photoexcited state (bright) and in the electrochemically oxidized ground state (dark).
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Affiliation(s)
- Ward van der Stam
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
- E-mail:
| | - Max de Graaf
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Solrun Gudjonsdottir
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jaco J. Geuchies
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jurgen J. Dijkema
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Nicholas Kirkwood
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Wiel H. Evers
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Alessandro Longo
- Netherlands
Organization for Scientific Research (NWO), Dutch-Belgian Beamline,
ESRF, The European Synchrotron, CS40220, 38043, 71 Avenue des Martyrs, 38000 Grenoble, France
- Istituto
per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR, UOS Palermo, Via Ugo La Malfa, 153, 90146 Palermo, Italy
| | - Arjan J. Houtepen
- Optoelectronic
Materials Section, Faculty of Applied Sciences, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
- E-mail:
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19
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Yu K, Yang Y, Wang J, Tang X, Xu QH, Wang GP. Ultrafast carrier dynamics and third-order nonlinear optical properties of AgInS 2/ZnS nanocrystals. NANOTECHNOLOGY 2018; 29:255703. [PMID: 29595519 DOI: 10.1088/1361-6528/aabab7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Broad photoluminescence (PL) emission, a large Stokes shift and extremely long-lived radiative lifetimes are the characteristics of ternary I-III-VI semiconductor nanocrystals (NCs), such as CuInS2 and AgInS2. However, the lack of understanding regarding the intriguing PL mechanisms and photo-carrier dynamics limits their further applications. Here, AgInS2 and AgInS2/ZnS NCs were chemically synthesized and their carrier dynamics were studied by time-resolved PL spectroscopy. The results demonstrated that the surface defect state, which contributed dominantly to the non-radiative decay processes, was effectively passivated through ZnS alloying. Femtosecond transient absorption spectroscopy was also used to investigate the carrier dynamics, revealing the electron storage at the surface state and donor state. Furthermore, the two photon absorption properties of AgInS2 and AgInS2/ZnS NCs were measured using an open-aperture Z-scan technique. The improved third-order nonlinear susceptibility [Formula: see text] of AgInS2 through ZnS alloying demonstrates potential application in two photon PL biological imaging.
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Affiliation(s)
- Kuai Yu
- College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060, People's Republic of China
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20
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Berends AC, van der Stam W, Akkerman QA, Meeldijk JD, van der Lit J, de Mello Donega C. Anisotropic 2D Cu 2-x Se Nanocrystals from Dodecaneselenol and Their Conversion to CdSe and CuInSe 2 Nanoparticles. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2018; 30:3836-3846. [PMID: 29910536 PMCID: PMC6002073 DOI: 10.1021/acs.chemmater.8b01143] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 05/09/2018] [Indexed: 05/28/2023]
Abstract
We present the synthesis of colloidal anisotropic Cu2-x Se nanocrystals (NCs) with excellent size and shape control, using the unexplored phosphine-free selenium precursor 1-dodecaneselenol (DDSe). This precursor forms lamellar complexes with Cu(I) that enable tailoring the NC morphology from 0D polyhedral to highly anisotropic 2D shapes. The Cu2-x Se NCs are subsequently used as templates in postsynthetic cation exchange reactions, through which they are successfully converted to CdSe and CuInSe2 quantum dots, nanoplatelets, and ultrathin nanosheets. The shape of the template hexagonal nanoplatelets is preserved during the cation exchange reaction, despite a substantial reorganization of the anionic sublattice, which leads to conversion of the tetragonal umangite crystal structure of the parent Cu2-x Se NCs into hexagonal wurtzite CdSe and CuInSe2, accompanied by a change of both the thickness and the lateral dimensions of the nanoplatelets. The crystallographic transformation and reconstruction of the product NCs are attributed to a combination of the unit cell dimensionalities of the parent and product crystal phases and an internal ripening process. This work provides novel tools for the rational design of shape-controlled colloidal anisotropic Cu2-x Se NCs, which, besides their promising optoelectronic properties, also constitute a new family of cation exchange templates for the synthesis of shape-controlled NCs of wurtzite CdSe, CuInSe2, and other metal selenides that cannot be attained through direct synthesis approaches. Moreover, the insights provided here are likely applicable also to the direct synthesis of shape-controlled NCs of other metal selenides, since DDSe may be able to form lamellar complexes with several other metals.
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Affiliation(s)
- Anne C. Berends
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O.
Box 80000, 3508 TA Utrecht, The Netherlands
| | - Ward van der Stam
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O.
Box 80000, 3508 TA Utrecht, The Netherlands
| | - Quinten A. Akkerman
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O.
Box 80000, 3508 TA Utrecht, The Netherlands
| | - Johannes D. Meeldijk
- Electron
Microscopy Utrecht, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CH Utrecht, Netherlands
| | - Joost van der Lit
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O.
Box 80000, 3508 TA Utrecht, The Netherlands
| | - Celso de Mello Donega
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O.
Box 80000, 3508 TA Utrecht, The Netherlands
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21
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Chen J, Li Y, Wang L, Zhou T, Xie RJ. Achieving deep-red-to-near-infrared emissions in Sn-doped Cu-In-S/ZnS quantum dots for red-enhanced white LEDs and near-infrared LEDs. NANOSCALE 2018; 10:9788-9795. [PMID: 29767202 DOI: 10.1039/c8nr01981a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Semiconductor quantum dots (QDs) are promising luminescent materials for use in lighting, display and bio-imaging, and the color tuning is a necessity for such applications. In this work, we report tunable colors and deep-red or near infrared (NIR) emissions in Cu-In-S and Cu-In-S/ZnS QDs by incorporating Sn. These QDs (with a size of 5 nm) with varying Sn concentrations and/or Cu/In ratios were synthesized by a non-injection method, and characterized by a variety of analytical techniques (i.e., XRD, TEM, XPS, absorption, photoluminescence, decay time, etc.). The Cu-Sn-In-S and Cu-Sn-In-S/ZnS QDs with Cu/In = 1/2 show the emission maximum in the ranges of 701-894 nm and 628-785 nm, respectively. The red-shift in emission is ascribed to the decrease of the band gap with the Sn doping. The highest quantum yield of 75% is achieved in Cu-Sn-In-S/ZnS with 0.1 mmol Sn and Cu/In = 1/2. Both the white and NIR LEDs were fabricated by using Cu-Sn-In-S/ZnS QDs and a 365 nm LED chip. The white LED exhibits superhigh color rendering indices of Ra = 97.2 and R9 = 91 and a warm color temperature of 2700 K. And the NIR LED shows an interesting broadband near-infrared emission centered at 741 nm, allowing for applications in optical communication, sensing and medical devices.
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Affiliation(s)
- Jixin Chen
- College of Materials, Xiamen University, Simingnan-Road 422, Xiamen 361005, P. R. China.
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22
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Berends AC, van der Stam W, Hofmann JP, Bladt E, Meeldijk JD, Bals S, de Mello Donega C. Interplay between Surface Chemistry, Precursor Reactivity, and Temperature Determines Outcome of ZnS Shelling Reactions on CuInS 2 Nanocrystals. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2018; 30:2400-2413. [PMID: 29657360 PMCID: PMC5895981 DOI: 10.1021/acs.chemmater.8b00477] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/23/2018] [Indexed: 05/05/2023]
Abstract
ZnS shelling of I-III-VI2 nanocrystals (NCs) invariably leads to blue-shifts in both the absorption and photoluminescence spectra. These observations imply that the outcome of ZnS shelling reactions on I-III-VI2 colloidal NCs results from a complex interplay between several processes taking place in solution, at the surface of, and within the seed NC. However, a fundamental understanding of the factors determining the balance between these different processes is still lacking. In this work, we address this need by investigating the impact of precursor reactivity, reaction temperature, and surface chemistry (due to the washing procedure) on the outcome of ZnS shelling reactions on CuInS2 NCs using a seeded growth approach. We demonstrate that low reaction temperatures (150 °C) favor etching, cation exchange, and alloying regardless of the precursors used. Heteroepitaxial shell overgrowth becomes the dominant process only if reactive S- and Zn-precursors (S-ODE/OLAM and ZnI2) and high reaction temperatures (210 °C) are used, although a certain degree of heterointerfacial alloying still occurs. Remarkably, the presence of residual acetate at the surface of CIS seed NCs washed with ethanol is shown to facilitate heteroepitaxial shell overgrowth, yielding for the first time CIS/ZnS core/shell NCs displaying red-shifted absorption spectra, in agreement with the spectral shifts expected for a type-I band alignment. The insights provided by this work pave the way toward the design of improved synthesis strategies to CIS/ZnS core/shell and alloy NCs with tailored elemental distribution profiles, allowing precise tuning of the optoelectronic properties of the resulting materials.
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Affiliation(s)
- Anne C. Berends
- Condensed
Matter and Interfaces, Debye Institute for
Nanomaterials Science, Utrecht University, Post Office Box 80000, 3508 TA Utrecht, The Netherlands
| | - Ward van der Stam
- Condensed
Matter and Interfaces, Debye Institute for
Nanomaterials Science, Utrecht University, Post Office Box 80000, 3508 TA Utrecht, The Netherlands
| | - Jan P. Hofmann
- Laboratory
of Inorganic Materials Chemistry, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, Postbox 513, 5600 MB Eindhoven, The Netherlands
| | - Eva Bladt
- EMAT,
Department of Physics, University of Antwerpen, Groenenborgerlaan 171, 2010 Antwerpen, Belgium
| | - Johannes D. Meeldijk
- Electron
Microscopy Utrecht, Debye Institute for
Nanomaterials Science, Utrecht University, 3584 CH Utrecht, Netherlands
| | - Sara Bals
- EMAT,
Department of Physics, University of Antwerpen, Groenenborgerlaan 171, 2010 Antwerpen, Belgium
| | - Celso de Mello Donega
- Condensed
Matter and Interfaces, Debye Institute for
Nanomaterials Science, Utrecht University, Post Office Box 80000, 3508 TA Utrecht, The Netherlands
- E-mail:
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23
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I-III-VI chalcogenide semiconductor nanocrystals: Synthesis, properties, and applications. CHINESE JOURNAL OF CATALYSIS 2018. [DOI: 10.1016/s1872-2067(18)63052-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Hughes KE, Hartstein KH, Gamelin DR. Photodoping and Transient Spectroscopies of Copper-Doped CdSe/CdS Nanocrystals. ACS NANO 2018; 12:718-728. [PMID: 29286633 DOI: 10.1021/acsnano.7b07879] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Colloidal Cu+-doped CdSe/CdS core/shell semiconductor nanocrystals (NCs) are investigated in their as-prepared and degenerately n-doped forms using time-resolved photoluminescence and transient-absorption spectroscopies. Photoluminescence from Cu+:CdSe/CdS NCs is dominated by recombination of delocalized conduction-band (CB) electrons with copper-localized holes. In addition to prominent bleaching of the first excitonic absorption feature, transient-absorption measurements show bleaching of the sub-bandgap copper-to-CB charge-transfer (MLCBCT) absorption band and also reveal a photoinduced midgap valence-band (VB)-to-copper charge-transfer (LVBMCT) absorption band that extends into the near-infrared, as predicted by recent computations. The photoluminescence of these NCs is substantially diminished upon introduction of excess CB electrons via photodoping. Time-resolved photoluminescence measurements reveal that the MLCBCT excited state is still formed upon photoexcitation of the n-doped Cu+:CdSe/CdS NCs, but its luminescence is quenched by a fast (picosecond) three-carrier trap-assisted Auger recombination process involving two CB electrons and one copper-bound hole.
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Affiliation(s)
- Kira E Hughes
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
| | - Kimberly H Hartstein
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
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25
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Chen B, Pradhan N, Zhong H. From Large-Scale Synthesis to Lighting Device Applications of Ternary I-III-VI Semiconductor Nanocrystals: Inspiring Greener Material Emitters. J Phys Chem Lett 2018; 9:435-445. [PMID: 29303589 DOI: 10.1021/acs.jpclett.7b03037] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Quantum dots with fabulous size-dependent and color-tunable emissions remained as one of the most exciting inventories in nanomaterials for the last 3 decades. Even though a large number of such dot nanocrystals were developed, CdSe still remained as unbeatable and highly trusted lighting nanocrystals. Beyond these, the ternary I-III-VI family of nanocrystals emerged as the most widely accepted greener materials with efficient emissions tunable in visible as well as NIR spectral windows. These bring the high possibility of their implementation as lighting materials acceptable to the community and also to the environment. Keeping these in mind, in this Perspective, the latest developments of ternary I-III-VI nanocrystals from their large-scale synthesis to device applications are presented. Incorporating ZnS, tuning the composition, mixing with other nanocrystals, and doping with Mn ions, light-emitting devices of single color as well as for generating white light emissions are also discussed. In addition, the future prospects of these materials in lighting applications are also proposed.
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Affiliation(s)
- Bingkun Chen
- Beijing Engineering Research Centre of Mixed Reality and Advanced Display, School of Optics and Photonics, Beijing Institute of Technology , Beijing 100081, China
| | - Narayan Pradhan
- Department of Materials Science, Indian Association for the Cultivation of Science , Kolkata, India 700032
| | - Haizheng Zhong
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology , Beijing 100081, China
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26
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Paderick S, Kessler M, Hurlburt TJ, Hughes SM. Synthesis and characterization of AgGaS2 nanoparticles: a study of growth and fluorescence. Chem Commun (Camb) 2018; 54:62-65. [PMID: 29206251 DOI: 10.1039/c7cc08070k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silver gallium sulfide nanocrystals demonstrate tunability for trap-state emission (650 nm) or band gap fluorescence (460 nm).
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27
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Pinchetti V, Lorenzon M, McDaniel H, Lorenzi R, Meinardi F, Klimov VI, Brovelli S. Spectro-electrochemical Probing of Intrinsic and Extrinsic Processes in Exciton Recombination in I-III-VI 2 Nanocrystals. NANO LETTERS 2017; 17:4508-4517. [PMID: 28613906 DOI: 10.1021/acs.nanolett.7b02040] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ternary CuInS2 nanocrystals (CIS NCs) are attracting attention as nontoxic alternatives to heavy metal-based chalcogenides for many technologically relevant applications. The photophysical processes underlying their emission mechanism are, however, still under debate. Here we address this problem by applying, for the first time, spectro-electrochemical methods to core-only CIS and core/shell CIS/ZnS NCs. The application of an electrochemical potential enables us to reversibly tune the NC Fermi energy and thereby control the occupancy of intragap defects involved in exciton decay. The results indicate that, in analogy to copper-doped II-VI NCs, emission occurs via radiative capture of a conduction-band electron by a hole localized on an intragap state likely associated with a Cu-related defect. We observe the increase in the emission efficiency under reductive electrochemical potential, which corresponds to raising the Fermi level, leading to progressive filling of intragap states with electrons. This indicates that the factor limiting the emission efficiency in these NCs is nonradiative electron trapping, while hole trapping is of lesser importance. This observation also suggests that the centers for radiative recombination are Cu2+ defects (preexisting and/or accumulated as a result of photoconversion of Cu1+ ions) as these species contain a pre-existing hole without the need for capturing a valence-band hole generated by photoexcitation. Temperature-controlled photoluminescence experiments indicate that the intrinsic limit on the emission efficiency is imposed by multiphonon nonradiative recombination of a band-edge electron and a localized hole. This process affects both shelled and unshelled CIS NCs to a similar degree, and it can be suppressed by cooling samples to below 100 K. Finally, using experimentally measured decay rates, we formulate a model that describes the electrochemical modulation of the PL efficiency in terms of the availability of intragap electron traps as well as direct injection of electrons into the NC conduction band, which activates nonradiative Auger recombination, or electrochemical conversion of the Cu2+ states into the Cu1+ species that are less emissive due to the need for their "activation" by the capture of photogenerated holes.
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Affiliation(s)
- Valerio Pinchetti
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , via R. Cozzi 55, I-20125 Milano, Italy
| | - Monica Lorenzon
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , via R. Cozzi 55, I-20125 Milano, Italy
| | - Hunter McDaniel
- UbiQD, Los Alamos, New Mexico 87544, United States
- Chemistry Division and Center for Advanced Solar Photophysics, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Roberto Lorenzi
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , via R. Cozzi 55, I-20125 Milano, Italy
| | - Francesco Meinardi
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , via R. Cozzi 55, I-20125 Milano, Italy
| | - Victor I Klimov
- Chemistry Division and Center for Advanced Solar Photophysics, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Sergio Brovelli
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , via R. Cozzi 55, I-20125 Milano, Italy
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28
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Nelson HD, Hinterding SOM, Fainblat R, Creutz SE, Li X, Gamelin DR. Mid-Gap States and Normal vs Inverted Bonding in Luminescent Cu+- and Ag+-Doped CdSe Nanocrystals. J Am Chem Soc 2017; 139:6411-6421. [DOI: 10.1021/jacs.7b01924] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Heidi D. Nelson
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Stijn O. M. Hinterding
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Rachel Fainblat
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Sidney E. Creutz
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Xiaosong Li
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Daniel R. Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
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29
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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: 394] [Impact Index Per Article: 56.3] [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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30
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Zang H, Li H, Makarov NS, Velizhanin KA, Wu K, Park YS, Klimov VI. Thick-Shell CuInS 2/ZnS Quantum Dots with Suppressed "Blinking" and Narrow Single-Particle Emission Line Widths. NANO LETTERS 2017; 17:1787-1795. [PMID: 28169547 DOI: 10.1021/acs.nanolett.6b05118] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Quantum dots (QDs) of ternary I-III-VI2 compounds such as CuInS2 and CuInSe2 have been actively investigated as heavy-metal-free alternatives to cadmium- and lead-containing semiconductor nanomaterials. One serious limitation of these nanostructures, however, is a large photoluminescence (PL) line width (typically >300 meV), the origin of which is still not fully understood. It remains even unclear whether the observed broadening results from considerable sample heterogeneities (due, e.g., to size polydispersity) or is an unavoidable intrinsic property of individual QDs. Here, we answer this question by conducting single-particle measurements on a new type of CuInS2 (CIS) QDs with an especially thick ZnS shell. These QDs show a greatly enhanced photostability compared to core-only or thin-shell samples and, importantly, exhibit a strongly suppressed PL blinking at the single-dot level. Spectrally resolved measurements reveal that the single-dot, room-temperature PL line width is much narrower (down to ∼60 meV) than that of the ensemble samples. To explain this distinction, we invoke a model wherein PL from CIS QDs arises from radiative recombination of a delocalized band-edge electron and a localized hole residing on a Cu-related defect and also account for the effects of electron-hole Coulomb coupling. We show that random positioning of the emitting center in the QD can lead to more than 300 meV variation in the PL energy, which represents at least one of the reasons for large PL broadening of the ensemble samples. These results suggest that in addition to narrowing size dispersion, future efforts on tightening the emission spectra of these QDs might also attempt decreasing the "positional" heterogeneity of the emitting centers.
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Affiliation(s)
| | | | | | | | | | - Young-Shin Park
- Center for High Technology Materials, University of New Mexico , Albuquerque, New Mexico 87131, United States
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31
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Berends AC, Rabouw FT, Spoor FCM, Bladt E, Grozema FC, Houtepen AJ, Siebbeles LDA, de Mello Donegá C. Radiative and Nonradiative Recombination in CuInS2 Nanocrystals and CuInS2-Based Core/Shell Nanocrystals. J Phys Chem Lett 2016; 7:3503-9. [PMID: 27552674 DOI: 10.1021/acs.jpclett.6b01668] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Luminescent copper indium sulfide (CIS) nanocrystals are a potential solution to the toxicity issues associated with Cd- and Pb-based nanocrystals. However, the development of high-quality CIS nanocrystals has been complicated by insufficient knowledge of the electronic structure and of the factors that lead to luminescence quenching. Here we investigate the exciton decay pathways in CIS nanocrystals using time-resolved photoluminescence and transient absorption spectroscopy. Core-only CIS nanocrystals with low quantum yield are compared to core/shell nanocrystals (CIS/ZnS and CIS/CdS) with higher quantum yield. Our measurements support the model of photoluminescence by radiative recombination of a conduction band electron with a localized hole. Moreover, we find that photoluminescence quenching in low-quantum-yield nanocrystals involves initially uncoupled decay pathways for the electron and hole. The electron decay pathway determines whether the exciton recombines radiatively or nonradiatively. The development of high-quality CIS nanocrystals should therefore focus on the elimination of electron traps.
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Affiliation(s)
- Anne C Berends
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80 000, 3508 TA Utrecht, The Netherlands
| | - Freddy T Rabouw
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80 000, 3508 TA Utrecht, The Netherlands
| | - Frank C M Spoor
- Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Eva Bladt
- Electron Microscopy for Materials Science (EMAT), University of Antwerp , Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Ferdinand C Grozema
- Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Arjan J Houtepen
- Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Laurens D A Siebbeles
- Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Celso de Mello Donegá
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80 000, 3508 TA Utrecht, The Netherlands
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32
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Knowles KE, Hartstein KH, Kilburn TB, Marchioro A, Nelson HD, Whitham PJ, Gamelin DR. Luminescent Colloidal Semiconductor Nanocrystals Containing Copper: Synthesis, Photophysics, and Applications. Chem Rev 2016; 116:10820-51. [DOI: 10.1021/acs.chemrev.6b00048] [Citation(s) in RCA: 233] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kathryn E. Knowles
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Kimberly H. Hartstein
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Troy B. Kilburn
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Arianna Marchioro
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Heidi D. Nelson
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Patrick J. Whitham
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Daniel R. Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
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33
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Jara DH, Stamplecoskie KG, Kamat PV. Two Distinct Transitions in Cu(x)InS2 Quantum Dots. Bandgap versus Sub-Bandgap Excitations in Copper-Deficient Structures. J Phys Chem Lett 2016; 7:1452-9. [PMID: 27043435 DOI: 10.1021/acs.jpclett.6b00571] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Cu-deficient CuInS2 quantum dots (QDs) synthesized by varying the [Cu]:[In] ratio allow modulation of optical properties as well as identification of the radiative emission pathways. Absorption and emission spectral features showed a strong dependence on the [Cu]:[In] ratio of CuxInS2 QDs, indicating two independent optical transitions. These effects are pronounced in transient absorption spectra. The bleaching of band edge absorption and broad tail absorption bands in the subpicosecond-nanosecond time scale provide further evidence for the dual optical transitions. The recombination process as monitored by photoemission decay indicated the involvement of surface traps in addition to the bandgap and sub-bandgap transitions. Better understanding of the origin of the optical transitions and their influence on the photodynamics will enable utilization of ternary semiconductor quantum dots in display and photovoltaic devices.
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Affiliation(s)
- Danilo H Jara
- Radiation Laboratory, Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Kevin G Stamplecoskie
- Radiation Laboratory, Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Prashant V Kamat
- Radiation Laboratory, Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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34
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Leach ADP, Macdonald JE. Optoelectronic Properties of CuInS2 Nanocrystals and Their Origin. J Phys Chem Lett 2016; 7:572-83. [PMID: 26758860 DOI: 10.1021/acs.jpclett.5b02211] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The capacity of fluorescent colloidal semiconductor nanocrystals for commercial application has led to the development of nanocrystals with nontoxic constituent elements as replacements for the currently available Cd- and Pb-containing systems. CuInS2 is a good candidate material because of its direct band gap in the near-infrared spectral region and large optical absorption coefficient. The ternary nature, flexible stoichiometry, and different crystal structures of CuInS2 lead to a range of optoelectronic properties, which have been challenging to elucidate. In this Perspective, the optoelectronic properties of CuInS2 nanocrystals are described and what is known of their origin is discussed. We begin with an overview of their synthesis, structure, and mechanism of formation. A complete discussion of the tunable luminescence properties and the radiative decay mechanism of this system is then presented. Finally, progress toward application of these "green" nanocrystals is summarized.
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Affiliation(s)
- Alice D P Leach
- Department of Chemistry and Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States
| | - Janet E Macdonald
- Department of Chemistry and Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States
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35
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Wu K, Liang G, Kong D, Chen J, Chen Z, Shan X, McBride JR, Lian T. Quasi-type II CuInS 2/CdS core/shell quantum dots. Chem Sci 2016; 7:1238-1244. [PMID: 29910880 PMCID: PMC5975837 DOI: 10.1039/c5sc03715h] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/12/2015] [Indexed: 02/03/2023] Open
Abstract
Ternary chalcopyrite CuInS2 quantum dots (QDs) have been extensively studied in recent years as an alternative to conventional QDs for solar energy conversion applications. However, compared with the well-established photophysics in prototypical CdSe QDs, much less is known about the excited properties of CuInS2 QDs. In this work, using ultrafast spectroscopy, we showed that both conduction band (CB) edge electrons and copper vacancy (VCu) localized holes were susceptible to surface trappings in CuInS2 QDs. These trap states could be effectively passivated by forming quasi-type II CuInS2/CdS core/shell QDs, leading to a single-exciton (with electrons delocalized among CuInS2/CdS CB and holes localized in VCu) half lifetime of as long as 450 ns. Because of reduced electron-hole overlap in quasi-type II QDs, Auger recombination of multiple excitons was also suppressed and the bi-exciton lifetime was prolonged to 42 ps in CuInS2/CdS QDs from 10 ps in CuInS2 QDs. These demonstrated advantages, including passivated trap states, long single and multiple exciton lifetimes, suggest that quasi-type II CuInS2/CdS QDs are promising materials for photovoltaic and photocatalytic applications.
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Affiliation(s)
- Kaifeng Wu
- Department of Chemistry , Emory University , 1515 Dickey Drive, NE , Atlanta , Georgia 30322 , USA .
| | - Guijie Liang
- Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices , Hubei University of Arts and Science , Xiangyang 441053 , Hubei Province , P. R. China
| | - Degui Kong
- College of Electronic Engineering , Heilongjiang University , Harbin 150080 , P. R. China
| | - Jinquan Chen
- Department of Chemistry , Emory University , 1515 Dickey Drive, NE , Atlanta , Georgia 30322 , USA .
| | - Zheyuan Chen
- Department of Chemistry , Emory University , 1515 Dickey Drive, NE , Atlanta , Georgia 30322 , USA .
| | - Xinhe Shan
- Department of Chemistry , Emory University , 1515 Dickey Drive, NE , Atlanta , Georgia 30322 , USA .
| | - James R McBride
- Department of Chemistry , The Vanderbilt Institute of Nanoscale Science and Engineering , Vanderbilt University , Nashville TN 37235 , USA
| | - Tianquan Lian
- Department of Chemistry , Emory University , 1515 Dickey Drive, NE , Atlanta , Georgia 30322 , USA .
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36
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Knowles KE, Nelson HD, Kilburn TB, Gamelin DR. Singlet-Triplet Splittings in the Luminescent Excited States of Colloidal Cu(+):CdSe, Cu(+):InP, and CuInS2 Nanocrystals: Charge-Transfer Configurations and Self-Trapped Excitons. J Am Chem Soc 2015; 137:13138-47. [PMID: 26389577 DOI: 10.1021/jacs.5b08547] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The electronic and magnetic properties of the luminescent excited states of colloidal Cu(+):CdSe, Cu(+):InP, and CuInS2 nanocrystals were investigated using variable-temperature photoluminescence (PL) and magnetic circularly polarized luminescence (MCPL) spectroscopies. The nanocrystal electronic structures were also investigated by absorption and magnetic circular dichroism (MCD) spectroscopies. By every spectroscopic measure, the luminescent excited states of all three materials are essentially indistinguishable. All three materials show very similar broad PL line widths and large Stokes shifts. All three materials also show similar temperature dependence of their PL lifetimes and MCPL polarization ratios. Analysis shows that this temperature dependence reflects Boltzmann population distributions between luminescent singlet and triplet excited states with average singlet-triplet splittings of ∼1 meV in each material. These similarities lead to the conclusion that the PL mechanism in CuInS2 NCs is fundamentally different from that of bulk CuInS2 and instead is the same as that in Cu(+)-doped NCs, which are known to luminesce via charge-transfer recombination of conduction-band electrons with copper-localized holes. The luminescence of CuInS2 nanocrystals is explained well by invoking exciton self-trapping, in which delocalized photogenerated holes contract in response to strong vibronic coupling at lattice copper sites to form a luminescent excited state that is essentially identical to that of the Cu(+)-doped semiconductor nanocrystals.
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Affiliation(s)
- Kathryn E Knowles
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
| | - Heidi D Nelson
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
| | - Troy B Kilburn
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States
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37
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Meinardi F, McDaniel H, Carulli F, Colombo A, Velizhanin KA, Makarov NS, Simonutti R, Klimov VI, Brovelli S. Highly efficient large-area colourless luminescent solar concentrators using heavy-metal-free colloidal quantum dots. NATURE NANOTECHNOLOGY 2015; 10:878-85. [PMID: 26301902 DOI: 10.1038/nnano.2015.178] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 07/16/2015] [Indexed: 05/20/2023]
Abstract
Luminescent solar concentrators serving as semitransparent photovoltaic windows could become an important element in net zero energy consumption buildings of the future. Colloidal quantum dots are promising materials for luminescent solar concentrators as they can be engineered to provide the large Stokes shift necessary for suppressing reabsorption losses in large-area devices. Existing Stokes-shift-engineered quantum dots allow for only partial coverage of the solar spectrum, which limits their light-harvesting ability and leads to colouring of the luminescent solar concentrators, complicating their use in architecture. Here, we use quantum dots of ternary I-III-VI2 semiconductors to realize the first large-area quantum dot-luminescent solar concentrators free of toxic elements, with reduced reabsorption and extended coverage of the solar spectrum. By incorporating CuInSexS2-x quantum dots into photo-polymerized poly(lauryl methacrylate), we obtain freestanding, colourless slabs that introduce no distortion to perceived colours and are thus well suited for the realization of photovoltaic windows. Thanks to the suppressed reabsorption and high emission efficiencies of the quantum dots, we achieve an optical power efficiency of 3.2%. Ultrafast spectroscopy studies suggest that the Stokes-shifted emission involves a conduction-band electron and a hole residing in an intragap state associated with a native defect.
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Affiliation(s)
- Francesco Meinardi
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, Milano I-20125, Italy
| | - Hunter McDaniel
- Center for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- UbiQD, Los Alamos, New Mexico 87544, USA
| | - Francesco Carulli
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, Milano I-20125, Italy
| | - Annalisa Colombo
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, Milano I-20125, Italy
| | - Kirill A Velizhanin
- Theoretical Division &Center for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Nikolay S Makarov
- Center for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Roberto Simonutti
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, Milano I-20125, Italy
| | - Victor I Klimov
- Center for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Sergio Brovelli
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, Milano I-20125, Italy
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