Symmetry‐Breaking Induced Interfacial Pyroelectricity for High‐Sensitivity Solar‐Blind Photodetection in Centrosymmetric Semiconductor

Pyroelectricity is a symmetry‐dependent effect supporting zero‐bias and ultrafast photoresponse, and traditionally realized only in non‐centrosymmetric materials for infrared detection. Nevertheless, the solar‐blind ultraviolet band offers low background noise, making it attractive for deep‐space exploration and secure communication. Centrosymmetric β‐Ga 2 O 3 , a promising candidate for solar‐blind ultraviolet detection, suffers from an inherent trade‐off between responsivity and response speed. Herein, the inversion symmetry limitation of ultrathin β‐Ga 2 O 3 is broken by asymmetric Schottky junction engineering, through which an interfacial polarization field is established, thereby introducing a pyroelectric effect. Systematic investigations reveal this effect originates from dynamic polarization variations within the Schottky depletion layer upon light switching, and can be modulated by an external electric field. Utilizing this effect, the device exhibits a great improvement in performance at 0 V bias, with responsivity enhanced by two orders of magnitude. Its response speed is markedly promoted, and the rise and decay times are accelerated from 300 and 525 ms to 10 and 11 µs. The ultrafast response and distinct bidirectional current signals enable high‐speed solar‐blind optical communication with bipolar signal decoding capability. This work establishes interfacial polarization as a powerful strategy to overcome intrinsic material limitations, opening a promising pathway toward ultrafast, high‐sensitivity optoelectronic detection in centrosymmetric semiconductors.