ALD oxygen vacancy-rich amorphous Ga2O3 on three-dimensional urchin-like ZnO arrays for high-performance self-powered solar-blind photodetectors

The exploration of efficient self-powered solar-blind photodetectors is essential for applications in future sustainable optoelectronic systems. Herein, we demonstrate a photoelectrochemical (PEC)-type heterojunction-driven solar-blind detector constructed by atomic layer deposition (ALD) of oxygen vacancy-rich amorphous Ga2O3 on three-dimensional urchin-like ZnO nanorod arrays (3D V-O-Ga2O3/ZnO). The as-fabricated device achieves excellent solar-blind photodetection performance in terms of a high photoresponsivity of 7.97 mA W-1 at 0 V bias, an ultrahigh light to dark ratio of 6.93 x 10(4) under 266 nm light illumination as well as fast response and recovery times. The excellent performance originates from abundant oxygen vacancies in a-Ga2O3 as donors, high specific surface area and good interface contact enabled by the 3D ordered nanostructure, and high carrier separation rates benefited from the Ga2O3/ZnO heterojunction. Our research offers a feasible and cost-effective approach towards the realization of a high-performance self-powered photodetection system for various applications.

Automated summary

In this study, a photoelectrochemical (PEC)-type solar-blind detector constructed by atomic layer deposition (ALD) of oxygen vacancy-rich amorphous Ga2O3 on three-dimensional ZnO nanorod arrays was demonstrated. The device exhibited high photoresponsivity, ultrahigh light to dark ratio, and fast response and recovery times, which resulted from the abundant oxygen vacancies in Ga2O3, the three-dimensional ordered nanostructure, and the Ga2O3/ZnO heterojunction.