Harvesting Cool Daylight in Hybrid Organic–Inorganic Halides Microtubules through the Reservation of Pressure‐Induced Emission

Pressure-induced emission (PIE) is extensively studied in halide perovskites or derivative hybrid halides. However, owing to the soft inorganic lattice of these materials, the intense emission is barely retained under ambient conditions, thus largely limiting their practical applications in optoelectronics at atmospheric pressure. Here, remarkably enhanced emission in microtubules of the 0D hybrid halide (C5 H7 N2 )2 ZnBr4 ((4AMP)2 ZnBr4 ) is successfully achieved by means of pressure treatment at room temperature. Notably, the emission, which is over ten times more intense than the emission in the initial state, is retained under ambient conditions upon the complete release of pressure. Furthermore, the pressure processing enables the tuning of "sky blue light" before compression to "cool daylight" with a remarkable quantum yield of 88.52% after decompression, which is of considerable interest for applications in next-generation lighting and displays. The irreversible electronic structural transition, induced by the steric hindrance with respect to complexly configurational organic molecules 4AMP, is highly responsible for the eventual retention of PIE and tuning of the color temperature. The findings represent a significant step toward the capture of PIE under ambient conditions, thus facilitating its potential solid-state lighting applications.