Enhanced Photoluminescence and Photoresponsiveness of Eu 3+ Ions‐Doped CsPbCl 3 Perovskite Quantum Dots under High Pressure

Metal halide perovskite quantum dots (QDs) have garnered tremendous attention in optoelectronic devices owing to their excellent optical and electrical properties. However, these perovskite QDs are plagued by pressure‐induced photoluminescence (PL) quenching, which greatly restricts their potential applications. Herein, the unique optical and electrical properties of Eu 3+ ‐doped CsPbCl 3 QDs under high pressure are reported. Intriguingly, the PL of Eu 3+ ions displays an enhancement with pressure up to 10.1 GPa and still preserves a relatively high intensity at 22 GPa. The optical and structural analysis indicates that the sample experiences an isostructural phase transition at approximately 1.53 GPa, followed by an amorphous state evolution, which is simulated and confirmed through density functional theory calculations. The pressure‐induced PL enhancement of Eu 3+ ions can be associated with the enhanced energy transfer rate from excitonic state to Eu 3+ ions. The photoelectric performance is enhanced by compression and can be preserved upon the release of pressure, which is attributed to the decreased defect density and increased carrier mobility induced by the high pressure. This work enriches the understanding of the high‐pressure behavior of rare‐earth‐doped luminescent materials and proves that high pressure technique is a promising way to design and realize superior optoelectronic materials.