Exciton Dynamics and Optical Properties of Lead Halide Perovskite Nanocrystals: From Nanorods to Nanocubes

Abstract

Lead halide perovskites, particularly CsPbBr3, have emerged as leading light emitters for their spectral purity, brightness, and facile synthesis. Their soft, ionic lattice makes them unusually defect tolerant but introduces problems with stability. Additionally, dephasing mechanisms and coupling to phonons are not yet well understood in these semiconductors. In the first part of the thesis, I investigate highly confined, anisotropic CsPbBr3 nanorods, elucidating the photophysics governing their broad single-particle linewidths. I utilize ensemble and single particle photoluminescence techniques across a wide temperature range in order to pinpoint exciton-phonon coupling mechanisms, structural and surface effects, and spin mixing in these novel materials. In the second part of the thesis, I focus on the opposite size regime, where collective behaviour dominates the optical properties. I develop a novel spectroscopy to pinpoint dephasing mechanisms that could reduce superradiant and coherent emission in order to promote rational design and future integration of these nanocrystals into quantum information devices.