Investigation of Chalcogenide and Lead Halide Perovskites by Photoelectron Spectroscopy for Solar Cell Applications

Solar panels are devices formed by a stack of layers, where the interfaces play an important role in the extraction of photogenerated carriers to generate electrical current. Therefore, understanding the surfaces and the mechanisms involved in the charge transfer is essential for further developments of solar cell devices. In this thesis, photoelectron spectroscopy was employed as the state-of-the-art tool for the examination of surfaces and interfaces. Two classes of perovskites for solar energy production were investigated: chalcogenide perovskites and lead halide perovskites. In chalcogenide perovskites, the study concerned the chemical and electronic structures of the BaZrS3, including the character of the band edges. We were interested in the interfacial structure, energy matching and band bending for the lead halide perovskites. A detailed understanding of the electronic structure and charge transfer occurring at the interfaces is important knowledge for the design and improvement of devices.