1
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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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2
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Gumber S, Prezhdo OV. Energy-Conserving Surface Hopping for Auger Processes. J Chem Theory Comput 2024; 20:5408-5417. [PMID: 38902855 PMCID: PMC11238531 DOI: 10.1021/acs.jctc.4c00562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Auger-type processes are ubiquitous in nanoscale materials because quantum confinement enhances Coulomb interactions, and there exist large densities of states. Modeling Auger processes requires the modification of nonadiabatic (NA) molecular dynamics algorithms to include transitions caused by both NA and Coulomb couplings. The system is split into quantum and classical subsystems, e.g., electrons and vibrations, and as a result, energy conservation becomes nontrivial. In surface hopping, an electronic transition induced by NA coupling is accompanied by a classical velocity readjustment to ensure conservation of the total quantum-classical energy. A different treatment is needed for Auger transitions driven by Coulomb interactions. We develop a nonadiabatic molecular dynamics methodology that meticulously differentiates the energy redistribution accompanying hops induced by the NA coupling and the Coulomb interaction and correctly conserves the total energy at each transition. If the transition is driven by a Coulomb interaction, the hop energy is redistributed within the quantum electronic subsystem only. If the transition is NA, the energy is redistributed between the quantum and classical subsystems. Properly maintaining energy conservation for both types of transitions is crucial to generate a correct order of events, obtain accurate transition times, maintain a proper statistical distribution of state populations, and reach thermodynamic equilibrium. We test the method with biexciton annihilation and Auger-assisted hot electron relaxation in a CdSe quantum dot. The sequence of Auger and phonon-driven processes and the calculated time scales are in excellent agreement with the experimental results. The developed approach can be coupled with any surface-hopping method and provides a crucial practical advance to study charge-carrier dynamics in the nanoscale and condensed matter systems.
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Affiliation(s)
- Shriya Gumber
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
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3
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Bassani CL, van Anders G, Banin U, Baranov D, Chen Q, Dijkstra M, Dimitriyev MS, Efrati E, Faraudo J, Gang O, Gaston N, Golestanian R, Guerrero-Garcia GI, Gruenwald M, Haji-Akbari A, Ibáñez M, Karg M, Kraus T, Lee B, Van Lehn RC, Macfarlane RJ, Mognetti BM, Nikoubashman A, Osat S, Prezhdo OV, Rotskoff GM, Saiz L, Shi AC, Skrabalak S, Smalyukh II, Tagliazucchi M, Talapin DV, Tkachenko AV, Tretiak S, Vaknin D, Widmer-Cooper A, Wong GCL, Ye X, Zhou S, Rabani E, Engel M, Travesset A. Nanocrystal Assemblies: Current Advances and Open Problems. ACS NANO 2024; 18:14791-14840. [PMID: 38814908 DOI: 10.1021/acsnano.3c10201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
We explore the potential of nanocrystals (a term used equivalently to nanoparticles) as building blocks for nanomaterials, and the current advances and open challenges for fundamental science developments and applications. Nanocrystal assemblies are inherently multiscale, and the generation of revolutionary material properties requires a precise understanding of the relationship between structure and function, the former being determined by classical effects and the latter often by quantum effects. With an emphasis on theory and computation, we discuss challenges that hamper current assembly strategies and to what extent nanocrystal assemblies represent thermodynamic equilibrium or kinetically trapped metastable states. We also examine dynamic effects and optimization of assembly protocols. Finally, we discuss promising material functions and examples of their realization with nanocrystal assemblies.
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Affiliation(s)
- Carlos L Bassani
- Institute for Multiscale Simulation, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Greg van Anders
- Department of Physics, Engineering Physics, and Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Uri Banin
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Dmitry Baranov
- Division of Chemical Physics, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden
| | - Qian Chen
- University of Illinois, Urbana, Illinois 61801, USA
| | - Marjolein Dijkstra
- Soft Condensed Matter & Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Michael S Dimitriyev
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Efi Efrati
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
- James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
| | - Jordi Faraudo
- Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, E-08193 Bellaterra, Barcelona, Spain
| | - Oleg Gang
- Department of Chemical Engineering, Columbia University, New York, New York 10027, USA
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Nicola Gaston
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, The University of Auckland, Auckland 1142, New Zealand
| | - Ramin Golestanian
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077 Göttingen, Germany
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3PU, UK
| | - G Ivan Guerrero-Garcia
- Facultad de Ciencias de la Universidad Autónoma de San Luis Potosí, 78295 San Luis Potosí, México
| | - Michael Gruenwald
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Amir Haji-Akbari
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, USA
| | - Maria Ibáñez
- Institute of Science and Technology Austria (ISTA), 3400 Klosterneuburg, Austria
| | - Matthias Karg
- Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Tobias Kraus
- INM - Leibniz-Institute for New Materials, 66123 Saarbrücken, Germany
- Saarland University, Colloid and Interface Chemistry, 66123 Saarbrücken, Germany
| | - Byeongdu Lee
- X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Reid C Van Lehn
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53717, USA
| | - Robert J Macfarlane
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Bortolo M Mognetti
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, 1050 Brussels, Belgium
| | - Arash Nikoubashman
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
- Institut für Theoretische Physik, Technische Universität Dresden, 01069 Dresden, Germany
| | - Saeed Osat
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077 Göttingen, Germany
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
| | - Grant M Rotskoff
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Leonor Saiz
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - An-Chang Shi
- Department of Physics & Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Sara Skrabalak
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Ivan I Smalyukh
- Department of Physics and Chemical Physics Program, University of Colorado, Boulder, Colorado 80309, USA
- International Institute for Sustainability with Knotted Chiral Meta Matter, Hiroshima University, Higashi-Hiroshima City 739-0046, Japan
| | - Mario Tagliazucchi
- Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA Ciudad Autónoma de Buenos Aires, Buenos Aires 1428 Argentina
| | - Dmitri V Talapin
- Department of Chemistry, James Franck Institute and Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Alexei V Tkachenko
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Sergei Tretiak
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - David Vaknin
- Iowa State University and Ames Lab, Ames, Iowa 50011, USA
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
- The University of Sydney Nano Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Gerard C L Wong
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA
| | - Xingchen Ye
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Shan Zhou
- Department of Nanoscience and Biomedical Engineering, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - Eran Rabani
- Department of Chemistry, University of California and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- The Raymond and Beverly Sackler Center of Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 69978, Israel
| | - Michael Engel
- Institute for Multiscale Simulation, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Alex Travesset
- Iowa State University and Ames Lab, Ames, Iowa 50011, USA
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4
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Dai D, Agrawal S, Prezhdo OV, Long R. Impact of large A-site cations on electron-vibrational interactions in 2D halide perovskites: Ab initio quantum dynamics. J Chem Phys 2024; 160:114704. [PMID: 38506296 DOI: 10.1063/5.0202251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/03/2024] [Indexed: 03/21/2024] Open
Abstract
Using ab initio nonadiabatic molecular dynamics, we study the effect of large A-site cations on nonradiative electron-hole recombination in two-dimensional Ruddlesden-Popper perovskites HA2APb2I7, HA = n-hexylammonium, A = methylammonium (MA), or guanidinium (GA). The steric hindrance created by large GA cations distorts and stiffens the inorganic Pb-I lattice, reduces thermal structural fluctuations, and maintains the delocalization of electrons and holes at ambient and elevated temperatures. The delocalized charges interact more strongly in the GA system than in the MA system, and the charge recombination is accelerated. In contrast, replacement of only some MA cations with GA enhances disorder and increases charge lifetime, as seen in three-dimensional perovskites. This study highlights the key influence of structural fluctuations and disorder on the properties of charge carriers in metal halide perovskites, providing guidance for tuning materials' optoelectronic performance.
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Affiliation(s)
- Dandan Dai
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Sraddha Agrawal
- Department of Chemistry, University of Southern California, Los Angeles, California 90007, USA
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90007, USA
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
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5
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Wang L, Nughays R, Rossi TC, Oppermann M, Ogieglo W, Bian T, Shih CH, Guo TF, Pinnau I, Yin J, Bakr OM, Mohammed OF, Chergui M. Disentangling Thermal from Electronic Contributions in the Spectral Response of Photoexcited Perovskite Materials. J Am Chem Soc 2024; 146:5393-5401. [PMID: 38359303 PMCID: PMC10910496 DOI: 10.1021/jacs.3c12832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/11/2024] [Accepted: 01/25/2024] [Indexed: 02/17/2024]
Abstract
Disentangling electronic and thermal effects in photoexcited perovskite materials is crucial for photovoltaic and optoelectronic applications but remains a challenge due to their intertwined nature in both the time and energy domains. In this study, we employed temperature-dependent variable-angle spectroscopic ellipsometry, density functional theory calculations, and broadband transient absorption spectroscopy spanning the visible to mid-to-deep-ultraviolet (UV) ranges on MAPbBr3 thin films. The use of deep-UV detection opens a new spectral window that enables the exploration of high-energy excitations at various symmetry points within the Brillouin zone, facilitating an understanding of the ultrafast responses of the UV bands and the underlying mechanisms governing them. Our investigation reveals that the photoinduced spectral features remarkably resemble those generated by pure lattice heating, and we disentangle the relative thermal and electronic contributions and their evolutions at different delay times using combinations of decay-associated spectra and temperature-induced differential absorption. The results demonstrate that the photoinduced transients possess a significant thermal origin and cannot be attributed solely to electronic effects. Following photoexcitation, as carriers (electrons and holes) transfer their energy to the lattice, the thermal contribution increases from ∼15% at 1 ps to ∼55% at 500 ps and subsequently decreases to ∼35-50% at 1 ns. These findings elucidate the intricate energy exchange between charge carriers and the lattice in photoexcited perovskite materials and provide insights into the limited utilization efficiency of photogenerated charge carriers.
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Affiliation(s)
- Lijie Wang
- Laboratory
of Ultrafast Spectroscopy, ISIC and Lausanne Centre for Ultrafast
Science (LACUS), École Polytechnique
Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
- Advanced
Membranes and Porous Materials Center (AMPM), Division of Physical
Science and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Razan Nughays
- Advanced
Membranes and Porous Materials Center (AMPM), Division of Physical
Science and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Thomas C. Rossi
- Laboratory
of Ultrafast Spectroscopy, ISIC and Lausanne Centre for Ultrafast
Science (LACUS), École Polytechnique
Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Malte Oppermann
- Laboratory
of Ultrafast Spectroscopy, ISIC and Lausanne Centre for Ultrafast
Science (LACUS), École Polytechnique
Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
- Department
of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Wojciech Ogieglo
- Advanced
Membranes and Porous Materials Center (AMPM), Division of Physical
Science and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Tieyuan Bian
- Department
of Applied Physics, The Hong Kong Polytechnic
University, Kowloon 999077, Hong Kong, P. R. China
| | - Chun-Hua Shih
- Department
of Photonics, National Cheng Kung University, Tainan 701, Taiwan ROC
| | - Tzung-Fang Guo
- Department
of Photonics, National Cheng Kung University, Tainan 701, Taiwan ROC
| | - Ingo Pinnau
- Advanced
Membranes and Porous Materials Center (AMPM), Division of Physical
Science and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Jun Yin
- Department
of Applied Physics, The Hong Kong Polytechnic
University, Kowloon 999077, Hong Kong, P. R. China
| | - Osman M. Bakr
- KAUST
Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Omar F. Mohammed
- Advanced
Membranes and Porous Materials Center (AMPM), Division of Physical
Science and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- KAUST
Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Majed Chergui
- Laboratory
of Ultrafast Spectroscopy, ISIC and Lausanne Centre for Ultrafast
Science (LACUS), École Polytechnique
Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
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6
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Lim JWM, Guo Y, Feng M, Cai R, Sum TC. Making and Breaking of Exciton Cooling Bottlenecks in Halide Perovskite Nanocrystals. J Am Chem Soc 2024; 146:437-449. [PMID: 38158611 DOI: 10.1021/jacs.3c09761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Harnessing quantum confinement (QC) effects in semiconductors to retard hot carrier cooling (HCC) is an attractive approach for enabling efficient hot carrier extraction to overcome the Shockley-Queisser limit. However, there is a debate about whether halide perovskite nanocrystals (PNCs) can effectively exploit these effects. To address this, we utilized pump-probe and multipulse pump-push-probe spectroscopy to investigate HCC behavior in PNCs of varying sizes and cation compositions. Our results validate the presence of an intrinsic phonon bottleneck with clear manifestations of QC effects in small CsPbBr3 PNCs exhibiting slower HCC rates compared to those of larger PNCs. However, the replacement of inorganic Cs+ with organic cations suppresses this intrinsic bottleneck. Furthermore, PNCs exhibit distinct size-dependent HCC behavior in response to changes in the cold carrier densities. We attribute this to the enhanced exciton-exciton interactions in strongly confined PNCs that facilitate Auger heating. Importantly, our findings dispel the existing controversy and provide valuable insights into design principles for engineering QC effects in PNC hot carrier applications.
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Affiliation(s)
- Jia Wei Melvin Lim
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Yuanyuan Guo
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Minjun Feng
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Rui Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Tze Chien Sum
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
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7
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Strandell D, Mora Perez C, Wu Y, Prezhdo OV, Kambhampati P. Excitonic Quantum Coherence in Light Emission from CsPbBr 3 Metal-Halide Perovskite Nanocrystals. NANO LETTERS 2024; 24:61-66. [PMID: 38113396 DOI: 10.1021/acs.nanolett.3c03180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The decay of excited states via radiative and nonradiative paths is well understood in molecules and bulk semiconductors but less so in nanocrystals. Here, we perform time-resolved photoluminescence (t-PL) experiments on CsPbBr3 metal-halide perovskite nanocrystals, with a time resolution of 3 ps, sufficient to observe the decay of both excitons and biexcitons as a function of temperature. The striking result is that the radiative rate constant of the single exciton increases at low temperatures with an exponential functional form, suggesting quantum coherent effects with dephasing at high temperatures. The opposing directions of the radiative and nonradiative decay rate constants enable enhanced brightening of PL from excitons to biexcitons due to quantum effects, promoting a faster approach to the quantum theoretical limits of light emission. Ab initio quantum dynamics simulations reproduce the experimental observations of radiation controlled by quantum spatial coherence enhanced at low temperatures.
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Affiliation(s)
- Dallas Strandell
- Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada
| | - Carlos Mora Perez
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Yifan Wu
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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8
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Strandell DP, Zenatti D, Nagpal P, Ghosh A, Dirin DN, Kovalenko MV, Kambhampati P. Hot Excitons Cool in Metal Halide Perovskite Nanocrystals as Fast as CdSe Nanocrystals. ACS NANO 2024; 18:1054-1062. [PMID: 38109401 DOI: 10.1021/acsnano.3c10301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
The idea of phonon bottlenecks has long been pursued in nanoscale materials for their application in hot exciton devices, such as photovoltaics. Decades ago, it was shown that there is no quantum phonon bottleneck in strongly confined quantum dots due to their physics of quantum confinement. More recently, it was proposed that there are hot phonon bottlenecks in metal halide perovskites due to their physics. Recent work has called into question these bottlenecks in metal halide perovskites. Here, we compare hot exciton cooling in a range of sizes of CsPbBr3 nanocrystals from weakly to strongly confined. These results are compared to strongly confined CdSe quantum dots of two sizes and degrees of quantum confinement. CdSe is a model system as a ruler for measuring hot exciton cooling being fast, by virtue of its efficient Auger-assisted processes. By virtue of 3 ps time resolution, the hot exciton photoluminescence can now be directly observed, which is the most direct measure of the presence of hot excitons and their lifetimes. The hot exciton photoluminescence decays on nearly the same 2 ps time scale on both the weakly confined perovskite and the larger CdSe quantum dots, much faster than the 10 ps cooling predicted by transient absorption experiments. The smaller CdSe quantum dot has still faster cooling, as expected from quantum size effects. The quantum dots of perovskites show extremely fast hot exciton cooling, decaying faster than detection limits of <1 ps, even faster than the CdSe system, suggesting the efficiency of Auger processes in these metal halide perovskite nanocrystals and especially in their quantum dot form. These results across a range of sizes of nanocrystals reveal extremely fast hot exciton cooling at high exciton density, independent of composition, but dependent upon size. Hence these metal halide perovskite nanocrystals seem to cool heavily following quantum dot physics.
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Affiliation(s)
| | - 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
| | - Dmitry N Dirin
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, 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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9
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Akimov AV. Energy-Conserving and Thermally Corrected Neglect of Back-Reaction Approximation Method for Nonadiabatic Molecular Dynamics. J Phys Chem Lett 2023; 14:11673-11683. [PMID: 38109379 DOI: 10.1021/acs.jpclett.3c03029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
In this work, the energy-conserving and thermally corrected neglect of the back-reaction approximation approach for nonadiabatic molecular dynamics in extended atomistic systems is developed. The new approach introduces three key corrections to the original method: (1) it enforces the total energy conservation, (2) it introduces an explicit coupling of the system to its environment, and (3) it introduces a renormalization of nonadiabatic couplings to account for a difference between the instantaneous nuclear kinetic energy and the kinetic energy of guiding trajectories. In the new approach, an auxiliary kinetic energy variable is introduced as an independent dynamical variable. The new approach produces nonzero equilibrium populations, whereas the original neglect of the back-reaction approximation method does not. It yields population relaxation time scales that are favorably comparable to the reference values, and it introduces an explicit and controllable way of dissipating energy into a bath without an assumption of the bath being at equilibrium.
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Affiliation(s)
- Alexey V Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260 United States
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10
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Mondal N, Carwithen BP, Bakulin AA. Alloying metal cations in perovskite nanocrystals is a new route to controlling hot carrier cooling. LIGHT, SCIENCE & APPLICATIONS 2023; 12:276. [PMID: 37985751 PMCID: PMC10662473 DOI: 10.1038/s41377-023-01316-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Hot carrier cooling is slowed down upon alloying tin in lead-halide perovskite nanocrystals through the engineering of carrier-phonon and carrier-defect interactions.
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Affiliation(s)
- Navendu Mondal
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Ben P Carwithen
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Artem A Bakulin
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK.
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11
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Brosseau P, Ghosh A, Seiler H, Strandell D, Kambhampati P. Exciton-polaron interactions in metal halide perovskite nanocrystals revealed via two-dimensional electronic spectroscopy. J Chem Phys 2023; 159:184711. [PMID: 37962451 DOI: 10.1063/5.0173369] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
Metal halide perovskite nanocrystals have been under intense investigation for their promise in optoelectronic devices due to their remarkable physics, such as liquid/solid duality. This liquid/solid duality may give rise to their defect tolerance and other such useful properties. This duality means that the electronic states are fluctuating in time, on a distribution of timescales from femtoseconds to picoseconds. Hence, these lattice induced energy fluctuations that are connected to polaron formation are also connected to exciton formation and dynamics. We observe these correlations and dynamics in metal halide perovskite nanocrystals of CsPbI3 and CsPbBr3 using two-dimensional electronic (2DE) spectroscopy, with its unique ability to resolve dynamics in heterogeneously broadened systems. The 2DE spectra immediately reveal a previously unobserved excitonic splitting in these 15 nm NCs that may have a coarse excitonic structure. 2D lineshape dynamics reveal a glassy response on the 300 fs timescale due to polaron formation. The lighter Br system shows larger amplitude and faster timescale fluctuations that give rise to dynamic line broadening. The 2DE signals enable 1D transient absorption analysis of exciton cooling dynamics. Exciton cooling within this doublet is shown to take place on a slower timescale than within the excitonic continuum. The energy dissipation rates are the same for the I and Br systems for incoherent exciton cooling but are very different for the coherent dynamics that give rise to line broadening. Exciton cooling is shown to take place on the same timescale as polaron formation, revealing both as coupled many-body excitation.
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Affiliation(s)
- Patrick Brosseau
- Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada
| | - Arnab Ghosh
- Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada
| | - Helene Seiler
- Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada
| | - Dallas Strandell
- Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada
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