Spectroscopic Studies of Metal Halide Perovskite Materials

This thesis describes spectroscopic studies of mixed-halide and mixed-cation perovskites aimed at elucidating the processes of phase transition, phase segregation and material decomposition upon exterior stimuli such as light, heat or oxygen. Raman spectroscopy and in-situ photoluminescence spectroscopy are employed as key experimental techniques, with single crystals in particular studied to overcome limitations of studying polycrystalline thin films. These studies provide new insight into fundamental understanding Hybrid Organic-Inorganic perovskites (HOIPs) which will be of benefit for exploiting their performance in solar cells and beyond.