Date of Award
8-2022
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Physics and Astronomy
Committee Chair/Advisor
Apparao. M. Rao
Committee Member
Murray Daw
Committee Member
Chad Sosolik
Committee Member
Lin Zhu
Committee Member
Sriparna Bhattacharya
Abstract
Perovskites are a novel class of materials that have piqued the interest of researchers in photovoltaics, photodetectors, and optoelectronics. In this study, we measure and elucidate in situ ultrafast carrier dynamics in both organic and inorganic, lead, and non-lead-based halide perovskite thin films using ultrafast photocurrent spectroscopy (UPCS) with a sub-25 ps time resolution. The UPCS technique enables us to define carrier transport dynamics in spatial, temporal, and energy landscapes via measurements at different electric fields, laser intensities, and temperatures. Here we explore and analyze solution-processed bulk MAPbI3 and nanocrystalline CsPbI3-based devices and novel non-lead double-layered perovskite devices through UPCS. In particular, we elucidate carrier transport dynamics focusing on early-time phonon interactions and the role played by the material defects. From our data and analysis, we successfully elucidated the role of ultra-shallow trap levels in MAPbI3 for the first time, while in nanocrystalline CsPbI3, we identified the optical phonon responsible for carrier phonon scattering through the analysis of the transport index number. Regarding double-layered perovskites, spectroscopic analysis of their charge carrier dynamics revealed the feasibility of using them in future optoelectronic applications. The design of lead-free, environmentally friendly perovskites can potentially replace current lead-based materials.
Recommended Citation
Kobbekaduwa, Kanishka, "In Situ Study of Ultrafast Carrier Transport Dynamics in Perovskite Thin-Films" (2022). All Dissertations. 3157.
https://open.clemson.edu/all_dissertations/3157
Author ORCID Identifier
0000-0002-3414-741X