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Gao P, Cheng S, Liu J, Li J, Guo Y, Deng Z, Qin T, Wang A. Facile Synthesis of Highly Emissive All-Inorganic Manganese Bromide Compounds with Perovskite-Related Structures for White LEDs. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238259. [PMID: 36500354 PMCID: PMC9736304 DOI: 10.3390/molecules27238259] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022]
Abstract
Lead-free all-inorganic halide materials with different Mn2+-based crystal structures (Cs3MnBr5 and CsMnBr3) were obtained using a convenient synthetic method. Cs3MnBr5 had a bright green emission (522 nm), with a unique single-exponential lifetime (τavg = 236 µs) and a high photoluminescence quantum yield (82 ± 5%). A red emission was observed in the case of the CsMnBr3 structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 µs (93%) and 18.328 µs (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs3MnBr5/CsMnBr3 was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs3MnBr5/CsMnBr3 with a commercial UV LED chip (365 nm).
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Affiliation(s)
- Ping Gao
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), Nanjing 211816, China
| | - Suwen Cheng
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), Nanjing 211816, China
| | - Jiaxin Liu
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), Nanjing 211816, China
| | - Junjie Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), Nanjing 211816, China
| | - Yanyan Guo
- State Key Laboratory of Analytical Chemistry for Life Science, National Laboratory of Micro-Structures, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China
| | - Zhengtao Deng
- State Key Laboratory of Analytical Chemistry for Life Science, National Laboratory of Micro-Structures, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China
| | - Tianshi Qin
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), Nanjing 211816, China
| | - Aifei Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), Nanjing 211816, China
- Correspondence:
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Nadtochenko V, Cherepanov D, Kochev S, Motyakin M, Kostrov A, Golub A, Antonova O, Kabachii Y, Rtimi S. Structural and optical properties of Mn2+-doped ZnCdS/ZnS core/shell quantum dots: New insights in Mn2+ localization for higher luminescence sensing. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.113946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Wu L, Wang Y, Kurashvili M, Dey A, Cao M, Döblinger M, Zhang Q, Feldmann J, Huang H, Debnath T. Interfacial Manganese‐Doping in CsPbBr
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Nanoplatelets by Employing a Molecular Shuttle. Angew Chem Int Ed Engl 2022; 61:e202115852. [PMID: 34995399 PMCID: PMC9305410 DOI: 10.1002/anie.202115852] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Indexed: 11/29/2022]
Abstract
Mn‐doping in cesium lead halide perovskite nanoplatelets (NPls) is of particular importance where strong quantum confinement plays a significant role towards the exciton–dopant coupling. In this work, we report an immiscible bi‐phasic strategy for post‐synthetic Mn‐doping of CsPbX3 (X=Br, Cl) NPls. A systematic study shows that electron‐donating oleylamine acts as a shuttle ligand to transport MnX2 through the water–hexane interface and deliver it to the NPls. The halide anion also plays an essential role in maintaining an appropriate radius of Mn2+ and thus fulfilling the octahedral factor required for the formation of perovskite crystals. By varying the thickness of parent NPls, we can tune the dopant incorporation and, consequently, the exciton‐to‐dopant energy transfer process in doped NPls. Time‐resolved optical measurements offer a detailed insight into the exciton‐to‐dopant energy transfer process. This new approach for post‐synthetic cation doping paves a way towards exploring the cation exchange process in several other halide perovskites at the polar–nonpolar interface.
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Affiliation(s)
- Linzhong Wu
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
- Institute of Functional Nano and Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Soochow University 199 Ren'ai Road Suzhou 215123 Jiangsu P. R. China
| | - Yiou Wang
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
| | - Mariam Kurashvili
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
| | - Amrita Dey
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
| | - Muhan Cao
- Institute of Functional Nano and Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Soochow University 199 Ren'ai Road Suzhou 215123 Jiangsu P. R. China
| | - Markus Döblinger
- Department of Chemistry Ludwig-Maximilians-Universität München Butenandtstrasse 5–13 (E) 81377 München Germany
| | - Qiao Zhang
- Institute of Functional Nano and Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Soochow University 199 Ren'ai Road Suzhou 215123 Jiangsu P. R. China
| | - Jochen Feldmann
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
| | - He Huang
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou 215006 P. R. China
| | - Tushar Debnath
- Chair for Photonics and Optoelectronics Nano-Institute Munich Department of Physics Ludwig-Maximilians-Universität München Königinstr. 10 80539 München Germany
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4
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Optical Properties of Mn-Doped CuGa(In)S-ZnS Nanocrystals (NCs): Effects of Host NC and Mn Concentration. NANOMATERIALS 2022; 12:nano12060994. [PMID: 35335807 PMCID: PMC8956066 DOI: 10.3390/nano12060994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 11/17/2022]
Abstract
Time-gated fluorescence measurement (TGFM) using long-life fluorescence probes is a highly sensitive fluorescence-measurement technology due to the inherently high signal-to-background ratio. Although many probes for TGFM such as luminescent-metal-complex probes and lanthanide-doped nanoparticles are in development, they generally need sophisticated/expensive instruments for biosensing/imaging applications. Probes possessing high brightness, low-energy (visible light) excitation, and long lifetimes up to milliseconds of luminescence, are highly desired in order to simplify the optical and electronic design of time-gated instruments (e.g., adopting non-UV-grade optics or low-speed electronics), lower the instrument complexity and cost, and facilitate broader applications of TGFM. In this work, we developed Mn-doped CuGa(In)S-ZnS nanocrystals (NCs) using simple and standard synthetic steps to achieve all the desired optical features in order to investigate how the optical properties (fluorescence/absorption spectra, brightness, and lifetimes) of the Mn-doped NCs are affected by different host NCs and Mn concentrations in host NCs. With optimal synthetic conditions, a library of Mn-doped NCs was achieved that possessed high brightness (up to 47% quantum yield), low-energy excitation (by 405 nm visible light), and long lifetimes (up to 3.67 ms). Additionally, the time-domain fluorescence characteristics of optimal Mn-doped NCs were measured under pulsed 405 nm laser excitation and bandpass-filter-based emission collection. The measurement results indicate the feasibility of these optimal Mn-doped NCs in TGFM-based biosensing/imaging.
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Bai X, Meng L, Zhou N, Zheng J, Yu XF, Chu PK, Xiao JJ, Zou B, Li J. In situ preparation of Mn-doped perovskite nanocrystalline films and application to white light emitting devices. J Colloid Interface Sci 2022; 606:1163-1169. [PMID: 34487935 DOI: 10.1016/j.jcis.2021.08.068] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022]
Abstract
Mn-doped perovskite nanocrystals have promised new optoelectronic applications due to their unique material properties. In the present study, Mn-doped perovskite nanocrystalline films were prepared in situ in a polymer matrix. The Mn-doped perovskite nanocrystals (PNCs) had good crystallinity and uniform size/spatial distributions in the polymer film. Bright dual-color emission and the long lifetime of the excited state of the dopant were observed from the host exciton and the Mn2+ dopant, respectively. Furthermore, magnetism was observed in the optimal Mn2+ concentration, implying that magnetic coupling was achieved in the Mn-doped perovskite lattice. The Mn-doped perovskite films also showed superior stability against moisture. To demonstrate the practicality of this composite film, a white light emitting device was fabricated by combining a single composite film with a blue light emitting diode; the device showed a high-quality white light emission, and the Commission Internationale De L'Eclairage (CIE) chromaticity coordinate of the white light emitting diode (WLED) (0.361, 0.326) was close to the optimal white color index. In this single-layer WLED, self-absorption among the luminous multilayers in traditional white light emitting diodes can be avoided. The study findings revealed that Mn-doped perovskite nanocrystalline films have many exciting properties, which bodes well for the fundamental study and design of high-performance optoelectronic devices.
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Affiliation(s)
- Xianwei Bai
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Lingqiang Meng
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ni Zhou
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jinju Zheng
- Institute of Materials, Ningbo University of Technology, Ningbo 315211, China
| | - Xue-Feng Yu
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Paul K Chu
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Jun-Jun Xiao
- College of Electronic and Information Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Bingsuo Zou
- Center on Nano-energy Research, School of Physical Science and Technology, and Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University, Nanning 530004, China.
| | - Jia Li
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
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6
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Debnath T, Wu L, Wang Y, Kurashvili M, Dey A, Cao M, Döblinger M, Zhang Q, Feldmann J, Huang H. Interfacial Manganese‐doping in CsPbBr3 Nanoplatelets by Employing a Molecular Shuttle. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tushar Debnath
- Ludwig-Maximilians-Universitat Munchen Physics Chair for Photonics and OptoelectronicsNano-Institute MünchenLudwig-Maximilians-Universität MünchenKöniginstr. 10 80539 Munich GERMANY
| | - Linzhong Wu
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen Department of Physics Königinstr. 10Nano-Institute München 80539 Munich GERMANY
| | - Yiou Wang
- Ludwig-Maximilians-Universitat Munchen Department of Physics Königinstr. 10Nano-Institute München 80539 Munich GERMANY
| | - Mariam Kurashvili
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen Department of Physics Königinstr. 10Nano-Institute München 8-539 Munich GERMANY
| | - Amrita Dey
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen Department of Physics Königinstr. 10Nano-Institute München 80539 Munich GERMANY
| | - Muhan Cao
- Soochow University Institute of Functional Nano & Soft Materials (FUNSOM) 199 Ren’ai Road 215123 Suzhou CHINA
| | - Markus Döblinger
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen Department of Chemistry Butenandtstrasse 5–13 (E) 81377 Munich GERMANY
| | - Qiao Zhang
- Soochow University Institute of Functional Nano & Soft Materials (FUNSOM) 199 Ren’ai Road 215123 Suzhou CHINA
| | - Jochen Feldmann
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen Department of Physics Königinstr. 10Nano-Institute Munich 80539 Munich GERMANY
| | - He Huang
- Ludwig-Maximilians-Universität München: Ludwig-Maximilians-Universitat Munchen Department of Physics Königinstr. 10Nano-Institute Munich 80539 Munich GERMANY
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7
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Ali F, Das S, Banerjee S, Maddala BG, Rana G, Datta A. Intense photoluminescence from Cu-doped CdSe nanotetrapods triggered by ultrafast hole capture. NANOSCALE 2021; 13:14228-14235. [PMID: 34477705 DOI: 10.1039/d1nr03833h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Brightly photoluminescent Cu-doped CdSe nanotetrapods (NTPs) have been prepared by a modified hot injection method. Their photoluminescence (PL) has a quantum yield of 38% and decays slowly over a few microseconds, while the PL in undoped NTPs has a rather small quantum yield of 1.7% and decays predominantly in tens of picoseconds, with a minor component in the nanosecond time regime. PL spectra of doped NTPs are significantly Stokes shifted compared to the band edge (BE). Efficient PL quenching by a hole scavenger confirms the oxidation state of +I for the dopant ion and establishes hole capture by this ion to be the primary event that leads to the Stokes shifted PL. A fast decay of the photoinduced absorption band, along with a similar decay in PL, observed in a femtosecond optical gating experiment, yields a time constant of about a picosecond for the hole capture from the valence band (VB) by Cu+. The remarkably long PL lifetime in the doped NTPs is ascribed to the decrease in the overlap between the wavefunctions of the photogenerated electrons and the captured hole. Hot carrier relaxation processes, triggered by excitation at energies greater than the band gap, leave their signature in a rise time of few hundreds of femtoseconds, in the ground state bleach recovery kinetics. Hence, a complete picture of exciton dynamics in the doped NTPs has been obtained using ultrafast spectroscopic techniques working in tandem.
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Affiliation(s)
- Fariyad Ali
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
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8
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Temperature-dependent anomalous Mn2+ emission and excited state dynamics in Mn2+-doped MAPbCl3-xBrx nanocrystals. J CHEM SCI 2021. [DOI: 10.1007/s12039-021-01919-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Jonnalagadda M, Prasad VB, Raghu AV. Synthesis of composite nanopowder through Mn doped ZnS-CdS systems and its structural, optical properties. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.129875] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Lorenz S, Erickson CS, Riesner M, Gamelin DR, Fainblat R, Bacher G. Directed Exciton Magnetic Polaron Formation in a Single Colloidal Mn 2+:CdSe/CdS Quantum Dot. NANO LETTERS 2020; 20:1896-1906. [PMID: 31999124 DOI: 10.1021/acs.nanolett.9b05136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
One of the most prominent signatures of transition-metal doping in colloidal nanocrystals is the formation of charge carrier-induced magnetization of the dopant spin sublattice, called exciton magnetic polaron (EMP). Understanding the direction of EMP formation, however, is still a major obstacle. Here, we present a series of temperature-dependent photoluminescence studies on single colloidal Mn2+:CdSe/CdS core/shell quantum dots (QDs) performed in a vector magnetic field providing a unique insight into the interaction between individual excitons and numerous magnetic impurities. The energy of the QD emission and its full width at half-maximum are controlled by the interplay of EMP formation and statistical magnetic fluctuations, in excellent agreement with theory. Most important, we give the first direct demonstration that anisotropy effects-hypothesized for more than a decade-dominate the direction of EMP formation. Our findings reveal a pathway for directing the orientation of optically induced magnetization in colloidal nanocrystals.
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Affiliation(s)
- Severin Lorenz
- 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
| | - Maurizio Riesner
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - 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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11
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Parobek D, Qiao T, Son DH. Energetic hot electrons from exciton-to-hot electron upconversion in Mn-doped semiconductor nanocrystals. J Chem Phys 2019; 151:120901. [PMID: 31575181 DOI: 10.1063/1.5119398] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Generation of hot electrons and their utilization in photoinduced chemical processes have been the subjects of intense research in recent years mostly exploring hot electrons in plasmonic metal nanostructures created via decay of optically excited plasmon. Here, we present recent progress made in generation and utilization of a different type of hot electrons produced via biphotonic exciton-to-hot electron "upconversion" in Mn-doped semiconductor nanocrystals. Compared to the plasmonic hot electrons, those produced via biphotonic upconversion in Mn-doped semiconductor nanocrystals possess much higher energy, enabling more efficient long-range electron transfer across the high energy barrier. They can even be ejected above the vacuum level creating photoelectrons, which can possibly produce solvated electrons. Despite the biphotonic nature of the upconversion process, hot electrons can be generated with weak cw excitation equivalent to the concentrated solar radiation without requiring intense or high-energy photons. This perspective reviews recent work elucidating the mechanism of generating energetic hot electrons in Mn-doped semiconductor nanocrystals, detection of these hot electrons as photocurrent or photoelectron emission, and their utilization in chemical processes such as photocatalysis. New opportunities that the energetic hot electrons can open by creating solvated electrons, which can be viewed as the longer-lived and mobile version of hot electrons more useful for chemical processes, and the challenges in practical utilization of energetic hot electrons are also discussed.
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Affiliation(s)
- David Parobek
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Tian Qiao
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Dong Hee Son
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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12
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Mukherjee A, Ray KK, Phadnis C, Layek A, Bera S, Chowdhury A. Insights on heterogeneity in blinking mechanisms and non-ergodicity using sub-ensemble statistical analysis of single quantum-dots. J Chem Phys 2019; 151:084701. [PMID: 31470698 DOI: 10.1063/1.5095870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Photo-luminescence (P-L) intermittency (or blinking) in semiconductor nanocrystals (NCs), a phenomenon ubiquitous to single-emitters, is generally considered to be temporally random intensity fluctuations between "bright" ("On") and "dark" ("Off") states. However, individual quantum-dots (QDs) rarely exhibit such telegraphic signals, and yet, a vast majority of single-NC blinking data are analyzed using a single fixed threshold which generates binary trajectories. Furthermore, while blinking dynamics can vary dramatically over NCs in the ensemble, the extent of diversity in the exponents (mOn/Off) of single-particle On-/Off-time distributions (P(tOn/Off)), often used to validate mechanistic models of blinking, remains unclear due to a lack of statistically relevant data sets. Here, we subclassify an ensemble of QDs based on the emissivity of each emitter and subsequently compare the (sub)ensembles' behaviors. To achieve this, we analyzed a large number (>1000) of blinking trajectories for a model system, Mn+2 doped ZnCdS QDs, which exhibits diverse blinking dynamics. An intensity histogram dependent thresholding method allowed us to construct distributions of relevant blinking parameters (such as mOn/Off). Interestingly, we find that single QD P(tOn/Off)s follow either truncated power law or power law, and their relative proportion varies over subpopulations. Our results reveal a remarkable variation in mOn/Off amongst as well as within subensembles, which implies multiple blinking mechanisms being operational amongst various QDs. We further show that the mOn/Off obtained via cumulative single-particle P(tOn/Off) is distinct from the weighted mean value of all single-particle mOn/Off, evidence for the lack of ergodicity. Thus, investigation and analyses of a large number of QDs, albeit for a limited time span of a few decades, are crucial to characterize the spatial heterogeneity in possible blinking mechanisms.
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Affiliation(s)
- Amitrajit Mukherjee
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Korak Kumar Ray
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Chinmay Phadnis
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Arunasish Layek
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Soumya Bera
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Arindam Chowdhury
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
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13
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Yuan Y, Han Y, Huang B, Zhang L, Yang H, Gu B, Cui Y, Zhang J. Single-channel UV/vis dual-band detection with ZnCdS:Mn/ZnS core/shell quantum dots. NANOTECHNOLOGY 2019; 30:075501. [PMID: 30523831 DOI: 10.1088/1361-6528/aaf3e0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the ultraviolet detection system, the Si-based photodetector could be sensitised with different kinds of fluorescent material to enhance its response in the short-wavelength range. Thick-shell ZnCdS:Mn/ZnS core/shell quantum dots (QDs) exhibit unique advantages in UV signal sensitisation due to their long PL lifetime, as well as stable emission matched with CCD's response. Herein, a single-channel UV panoramic detection system based on these Mn-doped QDs has been proposed. The QDs@PMMA film was attached on a Si-based CCD camera versus a tapered fibre, and an optical chopper was mounted before the QDs@PMMA film. The long lifetime fluorescence originating from UV signal could be still collected by the CCD camera when the chopper is in the 'off' state, hence the UV/vis signal ratio is significantly enhanced.
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Affiliation(s)
- Yufen Yuan
- Advanced Photonics Centre, Southeast University, Nanjing 210096, Jiangsu, People's Republic of China
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14
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Halder O, Satpati B, Rajput P, Mohapatra N, Jha SN, Suffczyński J, Pacuski W, Rath S. Light Emitting Spin Active Electronic States in Ultra-Thin Mn Doped CdSe Layered Nanosheets. Sci Rep 2019; 9:1804. [PMID: 30755677 PMCID: PMC6372604 DOI: 10.1038/s41598-019-38974-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/27/2018] [Indexed: 11/17/2022] Open
Abstract
The layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra- and inter- layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and co-existence of Mn2+ and Mn3+ based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. The optical absorption and photoluminescence (PL) studies at room temperature affirm wide array of optical properties in the visible regime corresponding to the band edge and intriguing dopant-phase mediated spin approved transitions. The circularly polarized magneto-PL and life time analysis exhibits the spin-polarized fast radiative transitions confirming the presence of spin-active electronic states.
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Affiliation(s)
- O Halder
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, 752 050, Khurda, India
| | - B Satpati
- Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700 064, India
| | - P Rajput
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - N Mohapatra
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, 752 050, Khurda, India
| | - S N Jha
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - J Suffczyński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 St., Warsaw, 02-093, Poland
| | - W Pacuski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 St., Warsaw, 02-093, Poland
| | - S Rath
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, 752 050, Khurda, India.
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15
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Renuga V, Mohan CN, Jaabir MSM, Prakash PA, Navaneethan M. Synthesis and Surface Passivation of CuInS 2/MnS/ZnS Core–Multishell Nanocrystals, Their Optical, Structural, and Morphological Characterization, and Their Bioimaging Applications. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b03482] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - M. Navaneethan
- Research Institute of Electronics, Shizuoka University, Hamamatsu, 4328011, Japan
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16
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Bhattacharyya B, Gahlot K, Viswanatha R, Pandey A. Optical Signatures of Impurity-Impurity Interactions in Copper Containing II-VI Alloy Semiconductors. J Phys Chem Lett 2018; 9:635-640. [PMID: 29337575 DOI: 10.1021/acs.jpclett.7b03087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We study the optical properties of copper containing II-VI alloy quantum dots (CuxZnyCd1-x-ySe). Copper mole fractions within the host are varied from 0.001 to 0.35. No impurity phases are observed over this composition range, and the formation of secondary phases of copper selenide are observed only at xCu > 0.45. The optical absorption and emission spectra of these materials are observed to be a strong function of xCu, and provide information regarding composition induced impurity-impurity interactions. In particular, the integrated cross section of optical absorption per copper atom changes sharply (from 1 × 10 -2 nm3 to 4 × 10 -2 nm3) at xCu = 0.12, suggesting a composition induced change in local electronic structure. These materials may serve as model systems to understand the electronic structure of I-III-VI2 semiconductor compounds.
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Affiliation(s)
- Biswajit Bhattacharyya
- Solid State and Structural Chemistry Unit, Indian Institute of Science , Bangalore-560012, India
| | - Kushagra Gahlot
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bangalore-560064, India
| | - Ranjani Viswanatha
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bangalore-560064, India
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bangalore-560064, India
| | - Anshu Pandey
- Solid State and Structural Chemistry Unit, Indian Institute of Science , Bangalore-560012, India
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17
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Pradhan N, Das Adhikari S, Nag A, Sarma DD. Luminescence, Plasmonic, and Magnetic Properties of Doped Semiconductor Nanocrystals. Angew Chem Int Ed Engl 2017; 56:7038-7054. [DOI: 10.1002/anie.201611526] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/18/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Narayan Pradhan
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 India
| | - Samrat Das Adhikari
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 India
| | - Angshuman Nag
- Department of Chemistry and Centre for Energy Science; Indian Institute of Science Education and Research, IISER; Pune 411008 India
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bengaluru 560012 India
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18
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Pradhan N, Das Adhikari S, Nag A, Sarma DD. Dotierte Halbleiter-Nanokristalle: Lumineszenz, plasmonische und magnetische Eigenschaften. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Narayan Pradhan
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 Indien
| | - Samrat Das Adhikari
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 Indien
| | - Angshuman Nag
- Department of Chemistry and Centre for Energy Science; Indian Institute of Science Education and Research, IISER; Pune 411008 Indien
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bengaluru 560012 Indien
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19
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Hou L, Zhou W, Zou B, Zhang Y, Han J, Yang X, Gong Z, Li J, Xie S, Shi LJ. Spin-exciton interaction and related micro-photoluminescence spectra of ZnSe:Mn DMS nanoribbon. NANOTECHNOLOGY 2017; 28:105202. [PMID: 28077805 DOI: 10.1088/1361-6528/aa58f1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
For their spintronic applications the magnetic and optical properties of diluted magnetic semiconductors (DMS) have been studied widely. However, the exact relationships between the magnetic interactions and optical emission behaviors in DMS are not well understood yet due to their complicated microstructural and compositional characters from different growth and preparation techniques. Manganese (Mn) doped ZnSe nanoribbons with high quality were obtained by using the chemical vapor deposition (CVD) method. Successful Mn ion doping in a single ZnSe nanoribbon was identified by elemental energy-dispersive x-ray spectroscopy mapping and micro-photoluminescence (PL) mapping of intrinsic d-d optical transition at 580 nm, i.e. the transition of 4 T 1(4 G) → 6 A 1(6 s),. Besides the d-d transition PL peak at 580 nm, two other PL peaks related to Mn ion aggregates in the ZnSe lattice were detected at 664 nm and 530 nm, which were assigned to the d-d transitions from the Mn2+-Mn2+ pairs with ferromagnetic (FM) coupling and antiferromagnetic (AFM) coupling, respectively. Moreover, AFM pair formation goes along with strong coupling with acoustic phonon or structural defects. These arguments were supported by temperature-dependent PL spectra, power-dependent PL lifetimes, and first-principle calculations. Due to the ferromagnetic pair existence, an exciton magnetic polaron (EMP) is formed and emits at 460 nm. Defect existence favors the AFM pair, which also can account for its giant enhancement of spin-orbital coupling and the spin Hall effect observed in PRL 97, 126603(2006) and PRL 96, 196404(2006). These emission results of DMS reflect their relation to local sp-d hybridization, spin-spin magnetic coupling, exciton-spin or phonon interactions covering structural relaxations. This kind of material can be used to study the exciton-spin interaction and may find applications in spin-related photonic devices besides spintronics.
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Affiliation(s)
- Lipeng Hou
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing100081, People's Republic of China
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20
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Debnath T, Parui K, Maiti S, Ghosh HN. An Insight into the Interface through Excited-State Carrier Dynamics for Promising Enhancement of Power Conversion Efficiency in a Mn-Doped CdZnSSe Gradient Alloy. Chemistry 2017; 23:3755-3763. [DOI: 10.1002/chem.201605612] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Tushar Debnath
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre; Mumbai 400 085 India), Fax
| | - Kausturi Parui
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre; Mumbai 400 085 India), Fax
| | - Sourav Maiti
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre; Mumbai 400 085 India), Fax
- Department of Chemistry; Savitribai Phule Pune University; Pune 411007 India
| | - Hirendra N. Ghosh
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre; Mumbai 400 085 India), Fax
- Institute of Nano Science and Technology; Mohali Punjab 16062 India
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21
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Irfanullah M, Sharma DK, Chulliyil R, Layek A, De S, Chowdhury A. Heterogeneity in optical properties of near white-light emissive europium complex species revealed by spectroscopy of single nanoaggregates. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.10.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Kuzmanović M, Božanić DK, Milivojević D, Ćulafić DM, Stanković S, Ballesteros C, Gonzalez-Benito J. Sodium-alginate biopolymer as a template for the synthesis of nontoxic red emitting Mn2+-doped CdS nanoparticles. RSC Adv 2017. [DOI: 10.1039/c7ra11011a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Structural and optical characteristics of manganese doped cadmium sulfide nanoparticles prepared by in situ chemical synthesis using biocompatible Na-alginate biopolymer as a template is reported.
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Affiliation(s)
- M. Kuzmanović
- Department of Material Science and Engineering
- Faculty of Engineering and Architecture
- Ghent University
- Belgium
- Department of Materials Science and Engineering and Chemical Engineering
| | - D. K. Božanić
- Department of Materials Science and Engineering and Chemical Engineering
- IQMAAB
- Universidad Carlos III de Madrid
- 28911 Leganés (Madrid)
- Spain
| | - D. Milivojević
- University of Belgrade
- Vinča Institute of Nuclear Sciences
- 11001 Belgrade
- Serbia
| | - D. Mitić Ćulafić
- University of Belgrade
- Faculty of Biology
- Center for Genotoxicology and Ecogenotoxicology
- 11001 Belgrade
- Serbia
| | - S. Stanković
- University of Belgrade
- Faculty of Biology
- Center for Genotoxicology and Ecogenotoxicology
- 11001 Belgrade
- Serbia
| | - C. Ballesteros
- Department of Physics
- Universidad Carlos III de Madrid
- Avenida de la Universidad 30
- 28911 Leganés (Madrid)
- Spain
| | - J. Gonzalez-Benito
- Department of Materials Science and Engineering and Chemical Engineering
- IQMAAB
- Universidad Carlos III de Madrid
- 28911 Leganés (Madrid)
- Spain
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23
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Pandey A, Sarma DD. Recent Advances in Manganese Doped II-VI Semiconductor Quantum Dots. Z Anorg Allg Chem 2016. [DOI: 10.1002/zaac.201600368] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anshu Pandey
- Solid State and Structural Chemistry Unit; Indian Institute of Science; 560012 Bangalore India
| | - Dipankar Das Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; 560012 Bangalore India
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24
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Debnath T, Maiti S, Ghosh HN. Unusually Slow Electron Cooling to Charge-Transfer State in Gradient CdTeSe Alloy Nanocrystals Mediated through Mn Atom. J Phys Chem Lett 2016; 7:1359-1367. [PMID: 27003582 DOI: 10.1021/acs.jpclett.6b00348] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We have synthesized Mn-doped CdTeSe gradient alloy nanocrystals (NCs) by a colloidal synthetic method, and charge carrier dynamics have been revealed through ultrafast transient absorption (TA) spectroscopy. Due to the reactivity difference between Te and Se, a CdTe-rich core and CdSe-rich shell have been formed in the CdTeSe alloy with the formation of a gradient type II core-shell structure. Electron paramagnetic resonance studies suggest Mn atoms are located in the surface of the alloy NCs. Steady-state optical absorption and emission studies suggest formation of a charge-transfer (CT) state in which electrons are localized in a CdSe-rich shell and holes are localized in a CdTe-rich core which appears in the red region of the spectra. Electron transfer in the CT state is found to take place in the Marcus inverted region. To understand charge-transfer dynamics in the CdTeSe alloy NCs and to determine the effect of Mn doping on the alloy, ultrafast transient absorption studies have been carried out. In the case of the undoped alloy, formation of the CT state is found to take place through electron relaxation to the conduction band of the CT state with a time of 600 fs and through hole relaxation (from the CdSe-rich state to the CdTe-rich state) to the valence band of the CT state with a time scale of 1 ps. However, electron relaxation in the presence of Mn dopants takes place initially via an electron transfer to the Mn 3d state (d(5)) followed by transfer from the Mn 3d state (d(6)) to the CT state, which has been found to take place with a >700 ps time scale in addition to the hole relaxation time of 2 ps. Charge recombination time of the CT state is found to be extremely slow in the Mn-doped CdTeSe alloy NCs as compared to the undoped one, where the Mn atom acts as an electron storage center.
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Affiliation(s)
- Tushar Debnath
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - Sourav Maiti
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
- Department of Chemistry, Savitribai Phule Pune University , Ganeshkhind, Pune 411007, India
| | - Hirendra N Ghosh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India
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25
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Pradhan N. Red-Tuned Mn d-d Emission in Doped Semiconductor Nanocrystals. Chemphyschem 2016; 17:1087-94. [PMID: 26632423 DOI: 10.1002/cphc.201500953] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Indexed: 12/30/2022]
Abstract
Light-emitting Mn-doped semiconductor nanocrystals have been extensively studied for the last three decades for their intense and stable Mn d-d emission. In principle, this emission should be fixed at 585 nm (yellow), but recent studies have shown that the emission can be widely tuned even to 650 nm (red). This is a spectacular achievement as this would make Mn-doped nanocrystals efficient and tunable light emitters. Keeping these developments in view, the chemistry of the synthesis of these materials, their photophysical processes and the expected origins of their red emission are summarized in this Minireview. All the related important studies from 1992 onwards are chronologically discussed, and one particular case is elaborated on in detail. As these materials are potentially important for biology, and photovoltaic, sensing and light-emitting devices, this Minireview is expected to help researchers investigating the chemistry, physics and applications of these materials.
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Affiliation(s)
- Narayan Pradhan
- Department of Materials Science, Indian Association for the Cultivation of Science, Kolkata, 700032, India.
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26
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Jagadeeswararao M, Pal S, Nag A, Sarma DD. Electrical and Plasmonic Properties of Ligand-Free Sn4+-Doped In2O3(ITO) Nanocrystals. Chemphyschem 2016; 17:710-6. [DOI: 10.1002/cphc.201500973] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Metikoti Jagadeeswararao
- Department of Chemistry; Indian Institute of Science Education and Research (IISER); Pune 411008 India
| | - Somnath Pal
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bangalore 560012 India
| | - Angshuman Nag
- Department of Chemistry; Indian Institute of Science Education and Research (IISER); Pune 411008 India
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bangalore 560012 India
- Department of Physics and Astronomy; Uppsala University; Box 516 75120 Uppsala Sweden
- Council of Scientific and Industrial Research-Network of Institutes for Solar Energy (CSIR-NISE); New Delhi 110001 India
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27
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Swarnkar A, Chulliyil R, Ravi VK, Irfanullah M, Chowdhury A, Nag A. Colloidal CsPbBr3 Perovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots. Angew Chem Int Ed Engl 2015; 54:15424-8. [PMID: 26546495 DOI: 10.1002/anie.201508276] [Citation(s) in RCA: 416] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 11/12/2022]
Abstract
Traditional CdSe-based colloidal quantum dots (cQDs) have interesting photoluminescence (PL) properties. Herein we highlight the advantages in both ensemble and single-nanocrystal PL of colloidal CsPbBr3 nanocrystals (NCs) over the traditional cQDs. An ensemble of colloidal CsPbBr3 NCs (11 nm) exhibits ca. 90 % PL quantum yield with narrow (FWHM=86 meV) spectral width. Interestingly, the spectral width of a single-NC and an ensemble are almost identical, ruling out the problem of size-distribution in PL broadening. Eliminating this problem leads to a negligible influence of self-absorption and Förster resonance energy transfer, along with batch-to-batch reproducibility of NCs exhibiting PL peaks within ±1 nm. Also, PL peak positions do not alter with measurement temperature in the range of 25 to 100 °C. Importantly, CsPbBr3 NCs exhibit suppressed PL blinking with ca. 90 % of the individual NCs remain mostly emissive (on-time >85 %), without much influence of excitation power.
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Affiliation(s)
- Abhishek Swarnkar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008 (India)
| | - Ramya Chulliyil
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)
| | - Vikash Kumar Ravi
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008 (India)
| | - Mir Irfanullah
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)
| | - Arindam Chowdhury
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)
| | - Angshuman Nag
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008 (India).
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28
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Swarnkar A, Chulliyil R, Ravi VK, Irfanullah M, Chowdhury A, Nag A. Colloidal CsPbBr3Perovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201508276] [Citation(s) in RCA: 288] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Wang Y, Zhang Y, Jia M, Meng H, Li H, Guan Y, Feng L. Functionalization of Carbonaceous Nanodots from MnII-Coordinating Functional Knots. Chemistry 2015; 21:14843-50. [DOI: 10.1002/chem.201502463] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 12/13/2022]
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30
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Whitham PJ, Knowles KE, Reid PJ, Gamelin DR. Photoluminescence Blinking and Reversible Electron Trapping in Copper-Doped CdSe Nanocrystals. NANO LETTERS 2015; 15:4045-51. [PMID: 26007328 DOI: 10.1021/acs.nanolett.5b01046] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Single-particle photoluminescence blinking is observed in the copper-centered deep-trap luminescence of copper-doped CdSe (Cu(+):CdSe) nanocrystals. Blinking dynamics for Cu(+):CdSe and undoped CdSe nanocrystals are analyzed to identify the effect of Cu(+), which selectively traps photogenerated holes. Analysis of the blinking data reveals that the Cu(+):CdSe and CdSe nanocrystal "off"-state dynamics are statistically identical, but the Cu(+):CdSe nanocrystal "on" state is shorter lived. Additionally, a new and pronounced temperature-dependent delayed luminescence is observed in the Cu(+):CdSe nanocrystals that persists long beyond the radiative lifetime of the luminescent excited state. This delayed luminescence is analogous to the well-known donor-acceptor pair luminescence of bulk copper-doped phosphors and is interpreted as revealing metastable charge-separated excited states formed by reversible electron trapping at the nanocrystal surfaces. A mechanistic link between this delayed luminescence and the luminescence blinking is proposed. Collectively, these data suggest that electron (rather than hole) trapping/detrapping is responsible for photoluminescence intermittency in these nanocrystals.
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Affiliation(s)
- Patrick J Whitham
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Kathryn E Knowles
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Philip J Reid
- 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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31
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Cao S, Li C, Wang L, Shang M, Wei G, Zheng J, Yang W. Long-lived and well-resolved Mn²⁺ ion emissions in CuInS-ZnS quantum dots. Sci Rep 2014; 4:7510. [PMID: 25515207 PMCID: PMC5378940 DOI: 10.1038/srep07510] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/14/2014] [Indexed: 12/28/2022] Open
Abstract
CuInS2 (CIS) quantum dots (QDs) have tunable photoluminescence (PL) behaviors in the visible and near infrared spectral range with markedly lower toxicity than the cadmium-based counterparts, making them very promising applications in light emitting and solar harvesting. However, there still remain material- and fabrication- related obstacles in realizing the high-performance CIS-based QDs with well-resolved Mn2+d-d emission, long emission lifetimes as well as high efficiencies. Here, we demonstrate the growth of high-quality Mn2+-doped CuInS-ZnS (CIS-ZnS) QDs based on a multi-step hot-injection strategy. The resultant QDs exhibit a well-resolved Mn2+d-d emission with a high PL quantum yield (QY) up to 66% and an extremely long excited state lifetime up to ~3.78 ms, which is nearly two times longer than the longest one of “green” QDs ever reported. It is promising that the synthesized Mn2+-doped CIS-ZnS QDs might open new doors for their practical applications in bioimaging and opto/electronic devices.
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Affiliation(s)
- Sheng Cao
- 1] School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China [2] Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Chengming Li
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Lin Wang
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Minghui Shang
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Guodong Wei
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Jinju Zheng
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Weiyou Yang
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
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32
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Kamran MA, Liu R, Shi LJ, Li ZA, Marzi T, Schöppner C, Farle M, Zou B. Tunable emission properties by ferromagnetic coupling Mn(II) aggregates in Mn-doped CdS microbelts/nanowires. NANOTECHNOLOGY 2014; 25:385201. [PMID: 25180542 DOI: 10.1088/0957-4484/25/38/385201] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Tunable optical emission properties from ferromagnetic semiconductors have not been well identified yet. In this work, high-quality Mn(II)-doped CdS nanowires and micrometer belts were prepared using a controlled chemical vapor deposition technique. The Mn doping could be controlled with time, precursor concentration and temperature. These wires or belts can produce both tunable redshifted emissions and ferromagnetic responses simultaneously upon doping. The strong emission bands at 572, 651, 693, 712, 745, 768, 787 and 803 nm, due to the Mn(II) (4)T1((4)G) → (6)A1((6)s) d-d transition, can be detected and accounted for by the aggregation of Mn ions at Cd sites in the CdS lattice at high temperature. These aggregates with ferromagnetism and shifted luminescence are related to the excitonic magnetic polaron (EMP) and localized EMP formations; this is verified by ab initio calculations. The correlation between aggregation-dependent optical emissions and ferromagnetic responses not only presents a new size effect for diluted magnetic semiconductors (DMSs), but also supplies a possible way to study or modulate the ferromagnetic properties of a DMS and to fabricate spin-related photonic devices in the future.
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Affiliation(s)
- Muhammad Arshad Kamran
- Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, People's Republic of China
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33
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Debnath T, Maity P, Maiti S, Ghosh HN. Electron Trap to Electron Storage Center in Specially Aligned Mn-Doped CdSe d-Dot: A Step Forward in the Design of Higher Efficient Quantum-Dot Solar Cell. J Phys Chem Lett 2014; 5:2836-42. [PMID: 26278087 DOI: 10.1021/jz5012719] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Specially aligned surface-accumulated Mn-doped CdSe (MnCdSe) quantum dots (QDs) have been synthesized to study the effect of dopant atom on charge-carrier dynamics in QD materials. EPR studies suggest that the (4)T1 state of Mn(2+) lies above the conduction band of CdSe, and as a result no Mn-luminescence was observed from MnCdSe. Femtosecond transient absorption studies suggest that Mn atom introduces structural defects in surface-doped CdSe, which acts as electron trap center in doped QD for the photoexcited electron. Bromo-pyrogallol red (Br-PGR) were found to form strong charge-trasfer complex with both CdSe and MnCdSe QDs. Charge separation in both the CdSe/Br-PGR and MnCdSe/Br-PGR composites was found to take place in three different pathways by transferring the photoexcited hole of CdSe/MnCdSe QDs to Br-PGR, electron injection from photoexcited Br-PGR to the QDs, and direct electron transfer from the HOMO of Br-PGR to the conduction band of both the QDs. Hole-transfer dynamics are found to be quite similar (∼1.1 to 1.3 ps) for both of the systems and found to be independent of Mn doping. However, charge recombination dynamics was found to be much slower in the MnCdSe/Br-PGR system as compared with that in the CdSe/Br-PGR system, which confirms that the Mn dopant act as the electron storage center. As a consequence, the MnCdSe/Br-PGR system can be used as a better super sensitizer in quantum-dot-sensitized solar cell to increase efficiency further.
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Hazarika A, Pandey A, Sarma DD. Rainbow Emission from an Atomic Transition in Doped Quantum Dots. J Phys Chem Lett 2014; 5:2208-2213. [PMID: 26279535 DOI: 10.1021/jz500937x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although semiconductor quantum dots are promising materials for displays and lighting due to their tunable emissions, these materials also suffer from the serious disadvantage of self-absorption of emitted light. The reabsorption of emitted light is a serious loss mechanism in practical situations because most phosphors exhibit subunity quantum yields. Manganese-based phosphors that also exhibit high stability and quantum efficiency do not suffer from this problem but in turn lack emission tunability, seriously affecting their practical utility. Here, we present a class of manganese-doped quantum dot materials, where strain is used to tune the wavelength of the dopant emission, extending the otherwise limited emission tunability over the yellow-orange range for manganese ions to almost the entire visible spectrum covering all colors from blue to red. These new materials thus combine the advantages of both quantum dots and conventional doped phosphors, thereby opening new possibilities for a wide range of applications in the future.
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Affiliation(s)
- Abhijit Hazarika
- †Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Anshu Pandey
- †Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - D D Sarma
- †Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
- §Council of Scientific and Industrial Research - Network of Institute for Solar Energy (CSIR-NISE), Anusandhan Bhawan, New Delhi 110001, India
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Yuan X, Zheng J, Zeng R, Jing P, Ji W, Zhao J, Yang W, Li H. Thermal stability of Mn2+ ion luminescence in Mn-doped core-shell quantum dots. NANOSCALE 2014; 6:300-7. [PMID: 24192996 DOI: 10.1039/c3nr04319c] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The thermal stability of luminescence is important for the application of quantum dots (QDs) in light-emitting devices. The temperature-dependent photoluminescence (PL) intensities and decay times of Mn-doped ZnS, ZnSe, and ZnSeS alloyed core-shell QD films were studied in the temperature range from 80 to 500 K by steady-state and time-resolved PL spectroscopy. It was found that the thermal stability of Mn-doped QD emissions was significantly dependent on the shell thickness and the host bandgap, which was higher than that of workhorse CdSe QDs. Nearly no PL quenching took place in Mn:ZnS QDs with a thick ZnS shell, which kept a high PL quantum yield (QY) of ~50% even at 500 K; and the thermally stable PL was also observed in highly luminescent Mn:ZnSe and Mn:ZnSeS QDs with a quenching temperature over 200 °C. Further, the stability of Mn-doped QDs with different shell thickness at high temperature was also examined through heating-cooling cycling experiments. The PL quenching in the thick shell-coated Mn-doped QDs was almost totally recovered. The PL quenching mechanisms of the Mn(2+) ion emissions were discussed.
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Affiliation(s)
- Xi Yuan
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
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Rao MJ, Shibata T, Chattopadhyay S, Nag A. Origin of Photoluminescence and XAFS Study of (ZnS)1-x(AgInS2)x Nanocrystals. J Phys Chem Lett 2014; 5:167-173. [PMID: 26276197 DOI: 10.1021/jz402443y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Donor-Acceptor transition was previously suggested as a mechanism for luminescence in (ZnS)1-x(AgInS2)x nanocrystals. Here we show the participation of delocalized valence/conduction band in the luminescence. Two emission pathways are observed: Path-1 involves transition between a delocalized state and a localized state exhibiting higher energy and shorter lifetime (∼25 ns) and Path-2 (donor-acceptor) involves two localized defect states exhibiting lower emission energy and longer lifetime (>185 ns). Surprisingly, Path-1 dominates (82% for x = 0.33) for nanocrystals with lower x, in sharp difference with prior assignment. Luminescence peak blue shifts systematically by 0.57 eV with decreasing x because of this large contribution from Path-1. X-ray absorption fine structure (XAFS) study of (ZnS)1-x(AgInS2)x nanocrystals shows larger AgS4 tetrahedra compared with InS4 tetrahedra with Ag-S and In-S bond lengths 2.52 and 2.45 Å respectively, whereas Zn-S bond length is 2.33 Å along with the absence of second nearest-neighbor Zn-S-metal correlation.
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Affiliation(s)
- M Jagadeeswara Rao
- †Department of Chemistry, Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune, India 411008
| | - Tomohiro Shibata
- ‡MRCAT, Sector 10, Argonne National Laboratory, 9700 South Cass Avenue, Bldg 433B, Argonne, Illinois 60439, United States
| | - Soma Chattopadhyay
- ‡MRCAT, Sector 10, Argonne National Laboratory, 9700 South Cass Avenue, Bldg 433B, Argonne, Illinois 60439, United States
| | - Angshuman Nag
- †Department of Chemistry, Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune, India 411008
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Sambandam B, Muthukumar T, Arumugam S, Paulose PL, Manoharan PT. Davydov splitting in cadmium vacancy emission, ferromagnetism and photosensitivity in manganese incorporated CdS nanocrystals. RSC Adv 2014. [DOI: 10.1039/c4ra01899k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Surfactant and diamines-assisted CdS nanocrystals have Cd2+ vacancies with photoluminescence property. The neighbouring Cd2+–Cd2+ vacancies exhibit Davydov splitting. Addition of Mn2+ ions in these sites leads to ferromagnetism.
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Affiliation(s)
- Balaji Sambandam
- Department of Chemistry
- Indian Institute of Technology/Madras
- Chennai, India
| | | | - Sonachalam Arumugam
- Centre for High Pressure Research
- School of Physics
- Bharathidasan University
- Tiruchirappalli, India
| | - P. L. Paulose
- Department of Condensed Matter and Physics
- Tata Institute of Fundamental Research
- Mumbai, India
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Zheng J, Cao S, Wang L, Gao F, Wei G, Yang W. Temperature-dependent photoluminescence properties of Mn:ZnCdS quantum dots. RSC Adv 2014. [DOI: 10.1039/c4ra04402a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report the temperature-dependent photoluminescence of Mn:ZnCdS QDs with a high PL QY of 65% at 360 K.
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Affiliation(s)
- Jinju Zheng
- School of Mechanical Engineering
- Ningbo University of Technology
- Ningbo 315016, China
- Institute of Materials
- Ningbo University of Technology
| | - Sheng Cao
- Institute of Materials
- Ningbo University of Technology
- Ningbo 315016, China
| | - Lin Wang
- Institute of Materials
- Ningbo University of Technology
- Ningbo 315016, China
| | - Fengmei Gao
- Institute of Materials
- Ningbo University of Technology
- Ningbo 315016, China
| | - Guodong Wei
- Institute of Materials
- Ningbo University of Technology
- Ningbo 315016, China
| | - Weiyou Yang
- Institute of Materials
- Ningbo University of Technology
- Ningbo 315016, China
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