Open Access Version

Abstract:
Perovskite-based solar cell devices promise high efficiencies and low cost, but their use in PV is limited by several factors. In this thesis, I look at the different limiting factors, e.g., pin-holes, decomposition and the toxicity of Pb, which can be eliminated/controlled by using Cs for better stability, Sn for less toxicity, and SnF2 for better coverage and prevention of oxidation. The chemical and electronic structure of solution-processable hybrid organometallic (CH3NH3PbI(3–x)Clx) and completely inorganic (CsSnBr3) perovskite materials have been studied using x-ray and electron based spectroscopic techniques. The morphology and local elemental composition of CH3NH3PbI(3–x)Clx used as absorbers in PV devices, which define the film quality (properties) and influences the performance of the solar cell have been studied in detail. Further, the impact of water and light on the chemical structure of CH3NH3PbI(3–x)Clx is studied in-situ to gain insight into the degradation mechanism responsible for the short lifetime of the absorber and solar cell. For alternative, completely inorganic CsSnBr3 absorbers, the impact of SnF2, as an oxidation inhibitor on the chemical and electronic structure is studied to identify its role in the improved performance of the solar cell.