Title: Photoelectron Spectroscopy of Hybrid Perovskites: Literature Overview, Preliminary Results, and Future Outlook

Abstract: Over the last few years, we have seen an unprecedented rise in power conversion efficiency of lead halide perovskite-based thin film solar cells. However, the fundamental electronic properties within these materials still remain to be explored. Photoelectron spectroscopy is the most important tool for revealing the basic electronic structure of solids and will be a key factor in determining the rationale for further progress in the hybrid perovskite field. I will provide an overview of the literature findings in this field to date and a progress report on work being done in ORaCEL. Particular attention will be paid to ultrafast time-resolved studies (two-photon photoelectron spectroscopy) combined with angle-resolved photoemission spectroscopy (ARPES). Together, these enable a comprehensive perspective on the band structure (occupied and unoccupied) and excited state dynamics in the hybrid perovskite materials.