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Kambhampati P. Unraveling the excitonics of light emission from metal-halide perovskite quantum dots. NANOSCALE 2024; 16:15033-15058. [PMID: 39052235 DOI: 10.1039/d4nr01481b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Metal halide semicondictor perovskites have been under intense investigation for their promise in light absorptive applications like photovoltaics. They have more recently experienced interest for their promise in light emissive applications. A key aspect of perovskites is their glassy, ionic lattice that exhibits dynamical disorder. One possible result of this dynamical disorder is their strong coupling between electronic and lattice degrees of freedom which may confer remarkable properties for light emission such as defect tolerance. How does the system, comprised of excitons, couple to the bath, comprised of lattice modes? How does this system-bath interaction give rise to novel light emissive properties and how do these properties give insight into the nature of these materials? We review recent work from this group in which time-resolved photoluminescence spectroscopy is used to reveal such insights. Based upon a fast time resolution of 3 ps, energy resolution, and temperature dependence, a wide variety of insights are gleaned. These insights include: lattice contributions to the emission linewidths, multiexciton formation, hot carrier cooling, excitonic fine structure, single dot superradiance, and a breakdown of the Condon approximation, all due to complex structural dynamics in these materials.
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Strandell D, Dirin D, Zenatti D, Nagpal P, Ghosh A, Raino G, Kovalenko MV, Kambhampati P. Enhancing Multiexcitonic Emission in Metal-Halide Perovskites by Quantum Confinement. ACS NANO 2023; 17:24910-24918. [PMID: 38079478 DOI: 10.1021/acsnano.3c06497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Semiconductor metal halide perovskite nanocrystals have been under intense investigation for their promise in a variety of optoelectronic applications, which arises from their remarkable properties of defect tolerance and efficient light emission. Recently, quantum dot versions of perovskite nanocrystals have been available, enabling investigation of how quantum size effects control optical function and performance in these quantum dots (QD), past their well-known covalent II-VI analogues. We perform time-resolved photoluminescence (t-PL) experiments on CsPbBr3 perovskite nanocrystals spanning in diameter from 5.8 nm strongly confined quantum dots to 18 nm weakly confined quantum dots. Experiments are performed with sufficient time resolution of 3 ps to observe the interaction energies and recombination kinetics from excitons to multiexcitons. Comparing the same sized QD reveals that perovskite QD have a larger radiative rate constant for emission from X than CdSe QD due to a larger oscillator strength. The multiexciton (MX) regime reveals that perovskite QD emit brightly and with more focused bandwidth than equivalent sized CdSe QD enabling more spectrally pure brightness. The MX kinetics reveals that the perovskite QD maintain efficient radiative decay, effectively competing with Auger recombination. These experiments reveal that the strongly confined QD of perovskites can be efficient multiexcitonic emitters, such as in high brightness light emitting diodes, especially in the blue.
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Affiliation(s)
- Dallas Strandell
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Dmitry Dirin
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Davide Zenatti
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Priya Nagpal
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Arnab Ghosh
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Gabriele Raino
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
- Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600 Dubendorf, Switzerland
| | - Maksym V Kovalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
- Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600 Dubendorf, Switzerland
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Tetyana P, Mphuthi N, Jijana AN, Moloto N, Shumbula PM, Skepu A, Vilakazi LS, Sikhwivhilu L. Synthesis, Characterization, and Electrochemical Evaluation of Copper Sulfide Nanoparticles and Their Application for Non-Enzymatic Glucose Detection in Blood Samples. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:481. [PMID: 36770442 PMCID: PMC9919628 DOI: 10.3390/nano13030481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/16/2022] [Accepted: 08/26/2022] [Indexed: 06/18/2023]
Abstract
Glutathione-capped copper sulfide (CuxSy) nanoparticles with two different average sizes were successfully achieved by using a simple reduction process that involves only changing the reaction temperature. Temperature-induced changes in the size of CuxSy nanoparticles resulted in particles with different optical, morphological, and electrochemical properties. The dependence of electrochemical sensing properties on the sizes of CuxSy nanoparticles was studied by using voltammetric and amperometric techniques. The spherical CuxSy nanoparticles with the average particle size of 25 ± 0.6 nm were found to be highly conductive as compared to CuxSy nanoparticles with the average particle size of 4.5 ± 0.2 nm. The spherical CuxSy nanoparticles exhibited a low bandgap energy (Eg) of 1.87 eV, resulting in superior electrochemical properties and improved electron transfer during glucose detection. The sensor showed a very good electrocatalytic activity toward glucose molecules in the presence of interference species such as uric acid (UA), ascorbic acid (AA), fructose, sodium chloride, and sucrose. These species are often present in low concentrations in the blood. The sensor demonstrated an excellent dynamic linear range between 0.2 to 16 mM, detection limit of 0.2 mM, and sensitivity of 0.013 mA/mM. The applicability of the developed sensor for real field determination of glucose was demonstrated by use of spiked blood samples, which confirmed that the developed sensor had great potential for real analysis of blood glucose levels.
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Affiliation(s)
- Phumlani Tetyana
- DSI/Mintek Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
- Department of Chemistry, University of Witwatersrand, Private Bag X3, Braamfontein 2050, South Africa
| | - Ntsoaki Mphuthi
- DSI/Mintek Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
- Department of Chemical Sciences, University of Johannesburg, Doornfontein 2028, South Africa
| | - Abongile Nwabisa Jijana
- DSI/Mintek Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
| | - Nosipho Moloto
- Department of Chemistry, University of Witwatersrand, Private Bag X3, Braamfontein 2050, South Africa
| | - Poslet Morgan Shumbula
- Department of Chemistry, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa
| | - Amanda Skepu
- Next Generation Health, Division 1, CSIR, Meiring Naude Road, Brummeria, Pretoria 0001, South Africa
| | - Lea Sibulelo Vilakazi
- DSI/Mintek Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
| | - Lucky Sikhwivhilu
- DSI/Mintek Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
- Department of Chemistry, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa
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Roy D, Ghosh S, De CK, Mukherjee S, Mandal S, Mandal PK. Excitation-Energy-Dependent Photoluminescence Quantum Yield is Inherent to Optically Robust Core/Alloy-Shell Quantum Dots in a Vast Energy Landscape. J Phys Chem Lett 2022; 13:2404-2417. [PMID: 35257586 DOI: 10.1021/acs.jpclett.2c00157] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The importance of alloy-shelling in optically robust Core/Alloy-Shell (CAS) QDs has been described from structural and energetic aspects. Unlike fluorescent dyes, both Core/Shell (CS) and CAS QDs exhibit excitation-energy-dependent photoluminescence quantum yield (PLQY). For both CdSe and InP CAS QDs (with metal- and nonmetal-based alloy-shelling, respectively), with increasing excitation energy, (a) the ultrafast rise-time or relaxation-time to the band-edge increases and (b) the magnitude of the normalized bleach signal decreases. Ultrasensitive single-particle spectroscopic investigation results showed that with decreasing excitation energy, (a) the fraction of ON events increases, (b) the ratio of exciton-detrapping rate/trapping rate increases, and (c) the extent of beneficial hole trapping increases. A relative decrease in PLQY with increasing excitation energy is much less pronounced in CAS QDs than in CS QDs. Unless trap states are removed completely especially in the higher-energy landscape, PLQY will remain inherently dependent on excitation energy for QDs in the vast energy landscape. When reporting the PLQY of QDs, the magnitude of the excitation energy must be mentioned.
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Affiliation(s)
- Debjit Roy
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, India 741246
| | - Swarnali Ghosh
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, India 741246
| | - Chayan K De
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, India 741246
| | - Soumen Mukherjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, India 741246
| | - Saptarshi Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, India 741246
| | - Prasun K Mandal
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, India 741246
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Zhang Z, Zhang S, Gushchina I, Guo T, Brennan MC, Pavlovetc IM, Grusenmeyer TA, Kuno M. Excitation Energy Dependence of Semiconductor Nanocrystal Emission Quantum Yields. J Phys Chem Lett 2021; 12:4024-4031. [PMID: 33880921 DOI: 10.1021/acs.jpclett.1c00811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Accurate measurements of semiconductor nanocrystal (NC) emission quantum yields (QYs) are critical to condensed phase optical refrigeration. Of particular relevance to measuring NC QYs is a longstanding debate as to whether an excitation energy-dependent (EED) QY exists. Various reports indicate existence of NC EED QYs, suggesting that the phenomenon is linked to specific ensemble properties. We therefore investigate here the existence of EED QYs in two NC systems (CsPbBr3 and CdSe) that are possible candidates for use in optical refrigeration. The influence of NC size, size-distribution, surface ligand, and as-made emission QYs are investigated. Existence of EED QYs is assessed using two approaches (an absolute approach using an integrating sphere and a relative approach involving excitation spectroscopy). Altogether, our results show no evidence of EED QYs across samples. This suggests that parameters beyond those mentioned above are responsible for observations of NC EED QYs.
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Affiliation(s)
- Zhuoming Zhang
- University of Notre Dame, Department of Chemistry and Biochemistry, Notre Dame, Indiana 46556, United States
| | - Shubin Zhang
- University of Notre Dame, Department of Physics, Notre Dame, Indiana 46556, United States
| | - Irina Gushchina
- University of Notre Dame, Department of Chemistry and Biochemistry, Notre Dame, Indiana 46556, United States
| | - Tianle Guo
- University of Notre Dame, Department of Chemistry and Biochemistry, Notre Dame, Indiana 46556, United States
| | - Michael C Brennan
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Ilia M Pavlovetc
- University of Notre Dame, Department of Chemistry and Biochemistry, Notre Dame, Indiana 46556, United States
| | - Tod A Grusenmeyer
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Masaru Kuno
- University of Notre Dame, Department of Chemistry and Biochemistry, Notre Dame, Indiana 46556, United States
- University of Notre Dame, Department of Physics, Notre Dame, Indiana 46556, United States
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Shi YE, Zhang P, Yang D, Wang Z. Synthesis, photoluminescence properties and sensing applications of luminescent sulfur nanodots. Chem Commun (Camb) 2020; 56:10982-10988. [PMID: 32804178 DOI: 10.1039/d0cc04341a] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sulfur nanodots (S-dots), composed of an elemental sulfur core and surface ligands, show unexpected photoluminescence (PL) properties, with the unique features of nontoxicity, hydrophilicity, high stability and easy modification. This review systematically introduces the synthesis methods, characterization, PL mechanisms and some typical applications of S-dots in chemical sensing. As the PL quantum yield (QY) is a key factor to evaluate the performance of luminescent materials, we report the synthesis methods according to the achievement in the promotion of PL QY. The PL mechanisms of S-dots are discussed from the view of the effects of the elemental sulfur core and passivated ligands on the PL QY and emission color. The design principle of analytical methods for various target molecules using S-dots is introduced. We end this review with the conclusions and some challenges in this field, which is expected to provide some clues for researchers in this field.
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Affiliation(s)
- Yu-E Shi
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry & Environmental Science, Hebei University, Baoding 071002, China.
| | - Peng Zhang
- Department of Pharmacy, Shenzhen Luohu People's Hospital, Shenzhen, 518001, China
| | - Daqing Yang
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry & Environmental Science, Hebei University, Baoding 071002, China.
| | - Zhenguang Wang
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry & Environmental Science, Hebei University, Baoding 071002, China.
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Sanderson WM, Wang F, Schrier J, Buhro WE, Loomis RA. Intraband Relaxation Dynamics of Charge Carriers within CdTe Quantum Wires. J Phys Chem Lett 2020; 11:4901-4910. [PMID: 32491860 DOI: 10.1021/acs.jpclett.0c01326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The state-to-state intraband relaxation dynamics of charge carriers photogenerated within CdTe quantum wires (QWs) are characterized via transient absorption spectroscopy. Overlapping signals from the energetic-shifting of the quantum-confinement features and the occupancy of carriers in the states associated with these features are separated using the quantum-state renormalization model. Holes generated with an excitation energy of 2.75 eV reach the band edge within the instrument response of the measurement, ∼200 fs. This extremely short relaxation time is consistent with the low photoluminescence quantum yield of the QWs, ∼0.2%, and the presence of alternative relaxation pathways for the holes. The electrons relax through the different energetically available quantum-confinement states, likely via phonon coupling, with an overall rate of ∼0.6 eV ps-1.
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Affiliation(s)
- William M Sanderson
- Department of Chemistry and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Fudong Wang
- Department of Chemistry and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Joshua Schrier
- Department of Chemistry, Fordham University, The Bronx, New York 10458, United States
| | - William E Buhro
- Department of Chemistry and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Richard A Loomis
- Department of Chemistry and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
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