【Domestic Papers】Enhancing the performance of Self-Powered Deep-Ultraviolet photoelectrochemical photodetectors by constructingα-Ga₂O₃@a-Al₂O₃ Core-Shell nanorod arrays for Solar-Blind imaging

      Researchers from the Chongqing Normal University have published a dissertation titled "Enhancing the performance of Self-Powered Deep-Ultraviolet photoelectrochemical photodetectors by constructing α-Ga₂O₃@a-Al₂O₃ Core-Shell nanorod arrays for Solar-Blind imaging " in Applied Surface Science.

Abstract

      With the advancement of Ga₂O₃-based deep-ultraviolet (DUV) photodetectors (PDs), the integration of PDs into array image sensors has become a sought-after objective. However, while solar-blind imaging research primarily revolves around solid-state Ga₂O₃-based PDs, there remains a significant gap in the exploration of novel photoelectrochemical (PEC) PDs for solar-blind imaging applications. In this study, self-powered solar-blind PEC-PDs with enhanced performance are fabricated based on α-Ga₂O₃@a-Al₂O₃ core–shell nanorod arrays (NRAs). Under DUV irradiation and without external bias, the α-Ga₂O₃@a-Al₂O₃ devices demonstrate remarkable superiority over α-Ga₂O₃ devices. When the light intensity was at 0.50 mW cm⁻², the photocurrent density notably rises from 4.60 to 11.24 μA cm⁻², accompanied by a corresponding increase in responsivity from 9.60 to 22.70 mA W⁻¹. The enhanced performance is attributed to the α-Ga₂O₃@a-Al₂O₃ heterostructure, which establishes a built-in electric field facilitating the separation and directed transport of photogenerated carriers at the interface. Moreover, for the first time, a 5 × 5 matrix of α-Ga₂O₃@a-Al₂O₃ core–shell NRAs-based PEC-type PDs is employed to demonstrate a proof-of-concept for self-powered solar-blind imaging, capable of effectively capturing the shapes of the letters “C” and “N”. This work underscores the immense potential of Ga₂O₃-based PEC-type PDs for future large-area solar-blind imaging applications.

Paper Link：https://doi.org/10.1016/j.apsusc.2023.159022