Mapping the Space of Inorganic and Hybrid Halides and Their Optical Properties Using Mechanochemistry and First-Principles Calculations

Inorganic and hybrid metal halides (MHs) are a class of ionic compounds that attract growing interest due to their richness of structure, properties, and resulting applications. These are largely ionic in nature and hence dominantly follow solid-state synthesis reactions rather than the solution approach. Keeping the importance of these materials in mind, herein, combination reactions of compounds via mechanochemistry is considered as a universal synthetic approach for the synthesis of MHs, and a library of MHs, including all inorganic MHs, ternary (A–B–X) MHs, enormous number of quaternary MHs based on representative 10 double perovskites (A–B–B′–X), and most of the hybrid ones based on randomly selected 49 samples as representative from the 1300 ones, are reported. The fundamental structure–property relationships are well revealed, where most of the MHs exhibit bright photoluminescence and/or magnetic properties for a few materials. Hence, the adopted concept of material design and related with their crystal structure and material properties for such a large number of halide materials not only help in building a library but also provide fundamental guidance to develop new MH materials with selective optoelectronic and magnetic properties..