Structural evolution and photoluminescence tuning of Bi3+/Sb3+ doped zero-dimensional perovskite [(CH3)3S]2SnCl6 under pressure

The tunable photoluminescence (PL) response of Bi3+/Sb3+ doped zero-dimensional perovskite [(CH3)3S]2SnCl6 via pressure-induced structure evolution is investigated using high-pressure techniques and density-functional theory calculations. In contrast to the rigidification of [SnCl6]2-/[SbCl6]3- octahedra by Sb3+ ions, Bi3+ ions trigger the distortion of the [SnCl6]2-/[BiCl6]3- octahedra at a relatively lower pressure, and even a cubic-to-trigonal phase transition of Bi3+ singly doped [(CH3)3S]2SnCl6 occurs at higher pressures due to its pressure sensitivity, wherein, the organic (CH3)3S+ chains enhance the flexibility of [(CH3)3S]2SnCl6 host structure. For Bi3+/Sb3+ doubly doped [(CH3)3S]2SnCl6, the two metal ion dopants interact with each other, accompanied by synergistic lattice distortion, resulting in novel self-trapped exciton emission behaviors in the host that is distinct from the single-ion doping effects. The pressure-dependent PL performance of Bi3+ and Sb3+ doped [(CH3)3S]2SnCl6 suggests its promising potential in the field of perovskite-based tunable light-emitting devices.