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...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis-Doctor of Philosophy |
| Language: | English |
| Published: |
Nanyang Technological University
2021
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/147004 |
| _version_ | 1826123036860874752 |
|---|---|
| author | Chang, Qing |
| author2 | Chia Ee Min, Elbert |
| author_facet | Chia Ee Min, Elbert Chang, Qing |
| author_sort | Chang, Qing |
| collection | NTU |
| 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. |
| first_indexed | 2024-10-01T05:58:24Z |
| format | Thesis-Doctor of Philosophy |
| id | ntu-10356/147004 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:58:24Z |
| publishDate | 2021 |
| publisher | Nanyang Technological University |
| record_format | dspace |
| spelling | ntu-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 |
| spellingShingle | Science::Physics Chang, Qing Carrier and exciton dynamics in halide perovskites |
| title | 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_short | Carrier and exciton dynamics in halide perovskites |
| title_sort | carrier and exciton dynamics in halide perovskites |
| topic | Science::Physics |
| url | https://hdl.handle.net/10356/147004 |
| work_keys_str_mv | AT changqing carrierandexcitondynamicsinhalideperovskites |