Lead-free broadband orange-emitting zero-dimensional Sb3+-doped indium-based organic–inorganic metal halides.

Low-dimensional organic–inorganic metal halides have shown great application potential and new opportunities for use in solid-state lighting due to their excellent optical and electronic properties. However, the most studied hybrid compounds contain lead, which limits their application environments. The preparation of organic–inorganic metal halides with high luminous efficiency, long-term stability, and a lead-free composition for environmental protection has become an important goal for the design of materials. Here, novel Sb3+-doped indium-based metal halides, (CH3NH3)4InCl6·Cl, have been designed and synthesized via a simple mechanical ball milling method; in the lead-free zero-dimensional (0D) halide (CH3NH3)4InCl6·Cl, isolated [InCl6]3− octahedra are separated by methylamine cations. Under UV excitation, the bulk-phase powder exhibits broadband orange-yellow emission peaking at 607 nm with a full width at half-maximum of ∼160 nm upon incorporating Sb3+ into the (CH3NH3)4InCl6·Cl matrix. The photoluminescence quantum yield (PLQY) of Sb3+-doped (CH3NH3)4InCl6·Cl is as high as 67.72%. The effects of the Sb3+-doping concentration on the crystal structure and optical characteristic have been investigated. The indirect band gap characteristics of (CH3NH3)4InCl6·Cl were demonstrated via density functional theory (DFT) calculations, and the relatively wide band gaps of 3.83 eV and 2.99 eV of (CH3NH3)4InCl6·Cl and (CH3NH3)4ClInCl6:Sb3+ were experimentally determined. These experimental results suggest that the as-prepared Sb3+-doped (CH3NH3)4InCl6·Cl has potential applications in solid-state lighting devices. [ABSTRACT FROM AUTHOR]