In Search of a Double Perovskite in the Phase Triangle of Bromides CsBr-CuBr-InBr.

New bromide compounds ABBBr with a double perovskite structure provide variety and flexibility of optoelectronic properties, and some of them are of poor toxicity in comparison with such popular lead halides. The promising compound with a double perovskite structure was proposed recently for the ternary system of CsBr-CuBr-InBr. Analysis of phase equilibria in the CsBr-CuBr-InBr ternary system showed stability of the quasi-binary section of CsCuBr-CsInBr.

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.