Lokal struktur hos metallhalidperovskiter undersökt med vibrationsspektroskopi

Abstract

Local Structure in Metal Halide Perovskites studied with Vibrational Spectroscopy The rapid development of metal halide perovskites has during the last decade positio ned the material as one of the most promising candidates for future energy technology such as solar cell technology, light emitting diodes, and photodetectors. Because metal halide perovskites are very flexible and in combination with the ease of synt hesizing the material, they are particularly attractive to use for technical applications. This bachelor’s thesis aims to analyze the local structure of the metal halide perov skite EAxMA1−xPbI3 and in particular to see how the local structure is affected by the cation composition x. By analyzing how the chemical composition affects the structure of the material at room temperature, new knowledge is obtained, which is of purely scientific interest, but can also be used as a reference for the purpose of optimizing stability and efficiency of the material. The scientific method for these studies involves infrared (IR) spectroscopy and Raman spectroscopy, together with studies of the materials photoluminescence. The reason behind this thesis is the stabilization challenges that currently limit the practical application of perovskites. The well-researched material MAPbI3 exhibits good qualities, but is sensitive to chemical degradation. Introducing EA+ is relevant since it shows potential to stabilize the structure, though it has not yet been studied how the substitution affects the properties of the material. This thesis shows how the cation composition has a direct and measurable impact on the local structure of the metal halide perovskites. The results present useful information that corresponds to relevant literature. The thesis might be useful in the next generation’s technical applications with customized features.