Metal Halide Perovskites:Composition, Physical Properties and Applications

The term metal halide perovskite encompasses all materials that adopt the perovskite crystal structure and contain metal and halide ions. One of the main strengths of this type of material is that the elements making up the structure can be exchanged for other ones, which lead to large group of metal halide perovskites with different properties and applications. Metal halide perovskites based on lead have been used in solar cells since 2009 and within a couple of years, they became comparable in efficiency with the commercially available solar cells. An advantage of these perovskite solar cells is that they can be processed from solution, simplifying the fabrication. This research investigates the role of different charge extraction layers in these solar cells to make them more efficient, and shows that this can be done by changing the electron transport layer. One downside of metal halide perovskite solar cells is that they are not as stable as their commercially available counterparts. We investigated new possible compositions of lead-based halide perovskites for the use in solar cells, with an emphasis on the stability of the material.Another part of the research focuses on copper-based perovskites. These materials adopt a two-dimensional configuration. We found that one of these perovskites can change color upon exposure to ultraviolet light, and identified the processes behind this change. Afterwards, we have used this material in vapor sensors and we demonstrated that these can detect 1-propanol, which presence in human breath is linked to lung cancer