Phase Equilibria in Ternary System CsBr-AgBr-InBr.

The double perovskite halides ABBX provide flexibility for various formulation adjustments and are of less toxicity in comparison with well-discussed complex lead halide derivatives. Such type of structure can be formed by replacing two Pb ions in the cubic lattice with a pair of non-toxic heterovalent (monovalent and trivalent) metal cations, such as silver and indium. The aim of this work is to briefly characterize the phase equilibria in the ternary system CsBr-AgBr-InBr and investigate the thermodynamic availability of synthesis of CsAgInBr double perovskite phase by solid-state sintering or melt crystallization. The results demonstrate the unfeasibility of the CsAgInBr phase but high stability of the corresponding binary bromides perspective for optoelectronics.