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

Abstract

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.