Pressure Regulated <i>π</i>–<i>π</i> Slip Enabling Blue‐Light Emission Enhancement of Terephthalic Acid

Abstract Organic solid‐state luminescent materials give rise to widespread applications in the fields of detection sensors, flexible displays, and optoelectronic devices. However, it remains a significant challenge to realize high‐efficiency emission in solid‐state organic systems owing to the undesired aggregation‐caused quenching. Herein, the extraordinary emission enhancement of solid‐state terephthalic acid (TPA) is successfully achieved under high pressure. Significantly, the high‐efficiency emission is unexpectedly captured down to the ambient conditions after pressure is completely released, where the photoluminescence quantum yield is remarkably increased from 26.5% to 74.1%. Experimental characterizations and first‐principles calculations reveal that the pressure treatment engineering endows the targeted TPA with enhanced hydrogen‐bond interactions decorated with slipped π – π staking arrangement. The targeted configuration restricts the vibration of chemical bonds and raises the rotational energy barrier of the pressure‐treated TPA, resulting in the suppression of nonradiative dissipation and the harvest of high‐performance blue‐light emission. This study provides crucial insights into the design of pressure‐responsive solid materials and significantly advances the development of organic solid luminescent materials.