Broadband light emitting zero-dimensional antimony and bismuth-based hybrid halides with diverse structures

Low-dimensional organic-inorganic metal halides have recently attracted extensive attention because of their various structures and distinguished photoelectric properties. Herein, we report a series of new zero-dimensional organic-inorganic hybrid metal halides: (TMEDA)3Bi2Cl12·H2O, (TMEDA)3Bi2Br12·H2O, (TMEDA)3Sb2Br12·H2O, and (TMEDA)5Sb6Cl28·2H2O [TMEDA = N,N,N′·trimethylethylenediamine]. (TMEDA)3M2X12·H2O (M = Bi or Sb, X = Cl or Br) crystallizes in the monoclinic space group P21/n, and (TMEDA)5Sb6Cl28·2H2O crystallizes in the orthorhombic space group Pnma. (TMEDA)3M2X12 possesses a zero-dimensional structure with the metal halide ions of [MBr6]3- isolated by the organic TMEDA2+ cations. Interestingly, the (TMEDA)5Sb6Cl28·2H2O structure consists of a combination of corner-connected octahedra [Sb4Cl18]6- and edge-shared [Sb2Cl10]4-, which is quite rare. The light emission of all these compounds was measured, and (TMEDA)3Sb2Br12·H2O exhibits the most intense luminescence. Upon 400 nm ultraviolet light excitation, (TMEDA)3Sb2Br12·H2O exhibited strong broadband yellow emission centered at 625 nm with a full-width at half-maximum of ∼150 nm originating from self-trapped excitons. This work suggests the possibility of new types of hybrid halides by introducing different metal centers and probing the structural evolution and photoluminescent properties, serving as a reference for the relationship between structure and luminescent performance and demonstrating their potential use as phosphors in light-emitting diodes.