Lina Ekstedt will defend her Master thesis about perovskite materials for photovoltaics. The work was performed in collaboration with Helmholtz Center Berlin.
Date and Time: 9 April 2021, at 13:00
Place: on Zoom, lu-se.zoom.us/j/67056738029
The project focuses on a certain group of perovskite materials that can be used as the absorber material in thin film solar cells. The perovskites studied belong to the series MAPb(Ix, Br1-x)3 and include chemical compositions with varying iodide to bromide ratios. By varying the halide ratio, the bandgap of the material can be tuned and hence the achievable output voltage of the solar cell. In this project the film formation process of the perovskites was studied in-situ and different parameters of it were investigated. The results show clear differences in the crystallization process of the materials depending on halide ratio and suggest that several parameters need to be optimized for each perovskite composition individually to achieve the best film quality and the best performance of the solar cells. For example, one of the parameters studied was adding an alkali salt to the solar cell stack prior to the deposition of the perovskite film, which clearly improved solar cells using perovskites with a very high iodide content, while it did not seem to necessarily benefit those with more bromide.