Uncovering White Light Emission in Pressure‐Treated Sb‐Doped Double Perovskite by Coherent Optical Phonon

Abstract

Single‐component white‐light emitters are ideal for solid‐state lighting applications. Here, the dual‐emission white light in the 3D Cs2NaInCl6:0.1 Sb3+ crystal is successfully achieved by the high‐pressure treatment strategy. Upon compression, the remarkable self‐trapped exciton (STE) emission enhancement is observed at 20.6 GPa due to the tilting and twisting of inorganic octahedron caused by the phase transition of Cs2NaInCl6:0.1 Sb3+ crystal. Intriguingly, after undergoing the high‐pressure treatment, in addition to the blue high‐energy emission from the STEs, [SbCl6]3− exhibits the orange low‐energy emission from STEs, which is ascribed to the remaining local distortion of inorganic octahedron resulting from the presence of residual amorphous phase in the local region upon decompression. Furthermore, coherent phonon generation and density functional theory calculations indicate that the electrons exhibit a strong coupling to A1g stretch mode and T2gIn bending mode in Cs2NaInCl6:0.1 Sb3+. After high‐pressure treatment, the coupling between the electrons and the T2gIn bending mode disappears, suggesting local octahedral symmetry disruption due to residual amorphous structures induced by high‐pressure treatment. This work unveils the relationship between the electron‐phonon coupling and the STE emission and offers a new strategy to design and synthesize the new single‐component white‐light metal halide perovskites.

Excitation-Dependent Emission in Sb3+-Doped All-Inorganic Rare-Earth Double Perovskites for Anticounterfeiting Applications

“…Recently, lead-free perovskites, such as double perovskites and low-dimensional perovskites, have attracted great interest in realizing excitation-dependent emission due to several intrinsic advantages including high photoluminescence quantum yields (PLQYs), low-toxicity, and low-cost solution processing. − These systems possess unique soft lattices and strong quantum confinement, which endow them with broadband self-trapped exciton (STE) emission. − The existence of multiple emission centers, including STEs, ligands, and doping ions, renders them a perfect platform to achieve excitation-dependent emission. − For example, Kuang et al reported a zero-dimensional (0D) indium–antimony alloyed halide perovskite, BAPPIn 1.996 Sb 0.004 Cl 10 , which emits bright yellow light and white light with PLQYs of ca. 100 and 44% at 320 and 365 nm excitation, respectively .…”

Time-Resolved Dynamics of Metal Halide Perovskite under High Pressure: Recent Progress and Challenges

“…The realization of dual-emission white light in the three-dimensional Cs 2 NaInCl 6 :0.1 Sb 3+ crystal was accomplished through a high-pressure treatment strategy . The observed intense Raman scattering in Cs 2 NaInCl 6 :0.1 Sb 3+ crystals underscore the robust coupling between electrons and Raman-active lattice vibrations.…”