Ultrafast carrier and phonon dynamics in lead halide perovskites

Abstract

Ultrafast carrier and phonon dynamics center at the heart of the modern physics and play a significant role in the optoelectronic properties of halide perovskites, which are emerging as versatile semiconductor materials for robust and novel optoelectronic devices, particularly in photovoltaics and light emitting diodes. Herein, we investigate the carrier and phonon dynamics, in terms of hot carrier cooling, carrier trapping and coherent phonon dynamics in halide perovskites through ultrafast optical spectroscopy measurement, theoretical modeling and ab-initio calculations. Specifically, in Chapter 3, we revealed the origins and mechanisms of slow hot carrier cooling in lead iodide perovskite films; In Chapter 4, we unveiled the effect of localized traps on the optical properties of lead bromide perovskites films; In Chapter 5, we investigated the lattice displacement and coherent phonon dynamics in 2D perovskite films. The studies conducted in this thesis provided physical insights into the carrier and phonon dynamics which are of fundamental importance for perovskite optoelectronics.