Exploring average and local structure of all-inorganic perovskite derivatives

Metal halide perovskites derivatives of general formula Cs3B2X9 with B= Bi, Sb and X=I, Br have been proposed as possible less toxic and more stable alternatives to lead-containing materials for a wide range of applications from photovoltaics. Despite the huge interest in their physical properties a comprehensive description of their structure, both at the average and local level, and their polymorphism is still lacking, hindering a better understanding of the correlation between structure and properties for these versatile materials.