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..