Structural Phases of CsPbBr₃ Under Varying P and T: Impact on Stability and Electronic Properties

Inorganic photovoltaic ABX₃ perovskite systems exhibit high energy conversion efficiencies and are more resistant to deterioration under air exposure than hybrid organic-inorganic equivalents. However, the properties of these systems under relevant environmental stimuli are not fully explored. Structural measurements on CsPbBr₃ under pressure and temperature changes combined with detailed DFT simulations and analysis were used to investigate their structural stability and electron transport. The complex pressure/temperature-structural phase diagram is revealed. The impact of the bond strengths on the deformation of the Pb and Cs coordination by Br under pressure is discussed. The intrinsic stability of this class of materials is commented on. Possible approaches to enhance physical properties will be reported.