Pressure Tuning of Optical Properties and Structures\nin All-Inorganic Halide Perovskite Rb₇Sb₃Cl₁₆

Abstract

All\nlead-free inorganic halide perovskites, as efficient solid-state\nlight emission materials, have become ideal green optoelectronic materials\nto replace lead halide perovskites for diversified lighting and display\napplications with their excellent stability. Here, we investigated\nthe pressure-derived optical and structural response of a zero-dimensional\nlead-free perovskite Rb₇Sb₃Cl₁₆ through\napplying controllable pressure. A pressure-induced blue shift of the\nbroadband emission was achieved, and it was followed by the emission\ncolor transformation from yellow to green, which was ascribed to the\nelectron–phonon coupling weakening and the suppression of structural\ndeformation upon lattice contraction. In parallel, the band gap was\nnarrowed by about 0.5 eV as a result of enhanced metal halide orbital\noverlap under high pressure. This work provides a fundamental understanding\nfor modulating the optical properties of the low-dimensional metal\nhalide perovskites.