1
|
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.
Collapse
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
| |
Collapse
|
2
|
Brosseau P, Jasrasaria D, Ghosh A, Seiler H, Palato S, Kambhampati P. Two-Dimensional Electronic Spectroscopy Reveals Dynamics within the Bright Fine Structure of CdSe Quantum Dots. J Phys Chem Lett 2024; 15:1702-1707. [PMID: 38316135 DOI: 10.1021/acs.jpclett.3c03378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Semiconductor quantum dots are characterized by a discrete excitonic structure featuring coarse as well as fine structure. The lowest fine structure states have splittings into bright-dark states which are now well confirmed by single dot spectroscopy. In contrast, the splitting of the lowest coarse exciton into bright-bright fine structure states has not been observed nor the dynamics between these states. Here, we use the unique combination of time and energy resolution of two-dimensional electronic spectroscopy to directly observe the fine structure splittings into a bright-bright doublet. These splittings are strongly size dependent, with population relaxation on the <100 fs time scale.
Collapse
Affiliation(s)
- Patrick Brosseau
- Department of Chemistry, McGill University, Montreal H3A 0G4, Canada
| | - Dipti Jasrasaria
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720-1460, United States
| | - Arnab Ghosh
- Department of Chemistry, McGill University, Montreal H3A 0G4, Canada
| | - Helene Seiler
- Department of Chemistry, McGill University, Montreal H3A 0G4, Canada
| | - Samuel Palato
- Department of Chemistry, McGill University, Montreal H3A 0G4, Canada
| | | |
Collapse
|
3
|
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.
Collapse
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
| | | |
Collapse
|