Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon‐Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, P.R. China
Abstract:
Perovskite formamidinium lead triiodide (FAPbI3) is a very promising photovoltaic material. Unfortunately, perovskite FAPbI3 converts to a hexagonal phase at ambient conditions. Herein we study the electronic structure of both perovskite and hexagonal FAPbI3 films using soft X‐ray absorption near edge structure (XANES) and density functional theory. We find that the C and N 2p states of FA hybridize with the Pb, I states at the conduction band minimum in hexagonal, but not perovskite, FAPbI3. We also demonstrate that C K‐edge XANES can be used to investigate shifts in the valence band in other organic‐inorganic hybrid perovskites.
Graphical summary of the electronic structure and C K‐edge XANES in both perovskite and hexagonal FAPbI3 highlighting our findings.
