Organic-inorganic hybrid perovskites : photophysics, thin film fabrication and solar cells

Organic-inorganic hybrid perovskite semiconductors have attracted an unprecedented research attention recently due to their outstanding photophysical properties and their use for diverse optoelectronic applications. Optoelectronic devices such as solar cells, light-emitting diodes, lasers, photodetectors, etc. have already been realized. The most outstanding application has been the perovskite solar cell with certified power conversion efficiency that has risen steeply from 3.8% to 24.2% in less than a decade. Although tremendous work has been done to develop the perovskite field to the present state-of-the-art, further understanding is needed to improve these materials and the optoelectronic devices if the goal of commercialization of especially the perovskite solar cell technology is to be achieved. Thus, the work presented in this thesis contributes to the understanding of the photophysics and optoelectronic properties of these materials and their application in solar cells. First, we show that defects in MAPbBr3 single crystals can be fully and reversibly passivated in the presence of atmospheric air, offering the potential application of these materials as gas sensors. Secondly, to overcome the usual crystallization of the undesired yellow phase in the FAPbI3 thin films, we devise a novel scalable technique to grow high-quality FAPbI3 films that are fully photoactive. Thirdly, we fabricate solar cells based on p-i-n and n-i-p device architectures and found that the device architecture and the interfaces are very essential in achieving highly performing perovskite solar cells. Lastly, we explore the effect of strontium insertion on the physical properties of FASnI3 thin films.