Carrier and exciton dynamics in halide perovskites

Ever since the first perovskite-based solar cell (PSC) was reported in 2009, reported power conversion efficiencies (PCEs) of PSCs showed a rapid increase from 3.8% to now 25.5%. The reasons for the high PCEs include the large absorption coefficients, high carrier mobilities, and long balanced elect...

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Main Author: Chang, Qing
Other Authors: Chia Ee Min, Elbert
Format: Thesis-Doctor of Philosophy
Language:English
Published: Nanyang Technological University 2021
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Online Access:https://hdl.handle.net/10356/147004
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spelling sg-ntu-dr.10356-1470042023-02-28T23:47:50Z Carrier and exciton dynamics in halide perovskites Chang, Qing Chia Ee Min, Elbert School of Physical and Mathematical Sciences ElbertChia@ntu.edu.sg Science::Physics Ever since the first perovskite-based solar cell (PSC) was reported in 2009, reported power conversion efficiencies (PCEs) of PSCs showed a rapid increase from 3.8% to now 25.5%. The reasons for the high PCEs include the large absorption coefficients, high carrier mobilities, and long balanced electron–hole diffusion lengths. Free carriers dominate at low excitation densities, while excitons at high excitation densities. The latter condition is widely used in light-emitting diodes and lasers. To determine the photovoltaic performance of PSCs, charge carrier transport properties of the perovskites should be characterized. In transient absorption (TA) spectroscopy, free carriers and excitons both contribute to the transient signals, while time-resolved THz spectroscopy (TRTS) is sensitive to both carriers and phonon modes in lead halide perovskites. Hence, these ultrafast techniques are useful tools to characterize the charge transport properties of lead halide perovskites. My thesis includes studies that use TA to disentangle the time-resolved free carrier and exciton contributions in mixed-cation lead mixed-halide perovskites, and also use TRTS to disentangle carrier and phonon dynamics in all-inorganic perovskites. Knowing the physics behind these materials after photoexcitation could give useful information to device scientists and sample growers. Doctor of Philosophy 2021-03-19T04:52:21Z 2021-03-19T04:52:21Z 2020 Thesis-Doctor of Philosophy Chang, Q. (2020). Carrier and exciton dynamics in halide perovskites. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/147004 https://hdl.handle.net/10356/147004 10.32657/10356/147004 en This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Physics
spellingShingle Science::Physics
Chang, Qing
Carrier and exciton dynamics in halide perovskites
description Ever since the first perovskite-based solar cell (PSC) was reported in 2009, reported power conversion efficiencies (PCEs) of PSCs showed a rapid increase from 3.8% to now 25.5%. The reasons for the high PCEs include the large absorption coefficients, high carrier mobilities, and long balanced electron–hole diffusion lengths. Free carriers dominate at low excitation densities, while excitons at high excitation densities. The latter condition is widely used in light-emitting diodes and lasers. To determine the photovoltaic performance of PSCs, charge carrier transport properties of the perovskites should be characterized. In transient absorption (TA) spectroscopy, free carriers and excitons both contribute to the transient signals, while time-resolved THz spectroscopy (TRTS) is sensitive to both carriers and phonon modes in lead halide perovskites. Hence, these ultrafast techniques are useful tools to characterize the charge transport properties of lead halide perovskites. My thesis includes studies that use TA to disentangle the time-resolved free carrier and exciton contributions in mixed-cation lead mixed-halide perovskites, and also use TRTS to disentangle carrier and phonon dynamics in all-inorganic perovskites. Knowing the physics behind these materials after photoexcitation could give useful information to device scientists and sample growers.
author2 Chia Ee Min, Elbert
author_facet Chia Ee Min, Elbert
Chang, Qing
format Thesis-Doctor of Philosophy
author Chang, Qing
author_sort Chang, Qing
title Carrier and exciton dynamics in halide perovskites
title_short Carrier and exciton dynamics in halide perovskites
title_full Carrier and exciton dynamics in halide perovskites
title_fullStr Carrier and exciton dynamics in halide perovskites
title_full_unstemmed Carrier and exciton dynamics in halide perovskites
title_sort carrier and exciton dynamics in halide perovskites
publisher Nanyang Technological University
publishDate 2021
url https://hdl.handle.net/10356/147004
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