Luminescence tuning in a zero-dimensional organic–inorganic hybrid metal halide family of (C 7 H 18 N 2 )MBr 4 (M = Cd, Zn, and Mn)

New (C 7 H 18 N 2 )MBr 4 (M = Cd, Zn, and Mn) hybrids show bright blue/green photoluminescence. Cd- and Zn-based halide powders exhibit another red luminescence from defect-induced self-trapped excitions, promising for lighting and anti-counterfeiting.