Subvalent bismuth monocation Bi+ photoluminescence in ternary halide crystals KAlCl4 and KMgCl3

► Monocation Bi+ can isomorphically substitute K+ in ternary chloride crystals. ► Bi+ doped ternary chlorides can be crystallized from Lewis acidic melts. ► Bi+ doped ternary chlorides possess broadband NIR luminescence.