Lead-free Perovskite with Distorted [InX₆]^3- Octahedron Induced by Organic Cation and Enhanced PLQY by Sb Doping

In-based halide perovskites have attracted a lot of attention because of their unique broadband emission properties. Herein, a series of In-based hybrid perovskites of (H₂MP)₂InCl₇·H₂O (1), (H₂EP)₂InCl₇·H₂O (2), (H₂MP)₂InBr₇·H₂O (3), and (H₂EP)₂InBr₇·H₂O (4) were synthesized under the control of halogen ions and organic cations. 1, 2, and 4 exhibit obvious photoluminescence properties with peaks at 392, 442, and 652 nm, respectively. The effects of the different components on the crystal structure and photoluminescence properties are discussed by calculating the structural distortion of the [InX₆]^3- octahedron. The photoluminescence properties of 1 and 4 were significantly improved after Sb³⁺ doping with PLQY values of 57.12 and 41.53%. Finally, a white LED was successfully fabricated with the two doped compounds coated onto the 365 nm blue LED chip.