A High-Rigidity Organic–Inorganic Metal Halide Hybrid Enabling Reversible and Enhanced Self-Trapped Exciton Emission under High Pressure
Yin Liang, Yingjie Jiang, Ke‐Zhao Du, Yang‐Peng Lin, Xinyuan Ma, Daping Qiu, Ziyu Wang, Yanglong Hou, Xiaoding Wei, Qing Zhang
Abstract
Zero-dimensional organic–inorganic metal halide hybrids provide ideal bulk-crystal platforms for exploring the pressure engineering of electron–phonon coupling (EPC) and self-trapped exciton (STE) emission at the molecular level. However, the low stiffness of inorganic clusters hinders the reversible tuning of these physical properties. Herein, we designed a Sb 3+ -doped metal halide with a high emission yield (89.4%) and high bulk modulus (35 GPa) that enables reversible and enhanced STE emission (20-fold) under pressure. The high lattice rigidity originates from the corner-shared cage-structured inorganic tetramers and ring-shaped organic ligands. Further, we reveal that the pressure-enhanced emission regime below 4.5 GPa is owing to the lattice hardening and preferably EPC strength reducing, while the pressure-insensitive emission regime within 4.5–8.5 GPa results from the enhanced intercluster Coulombic attraction force that resists intracluster compression. These results provide insights into the structure–property relation and molecular engineering of zero-dimensional metal halides toward wide-band and pressure-sensitive light sources.