Asymmetric Au electrode engineering toward high-performance self-powered GaN photodetectors

The demand for high-performance self-powered photodetectors is rapidly increasing due to the growing need for battery-free and maintenance-free sensing in large-scale sustainable electronics and long-lifetime autonomous systems. This study investigates the impact of Au electrode asymmetry on the self-powering mechanism of gallium nitride photodetectors (GaN PDs) under 302 nm and 365 nm UV illumination. The responsivity and detectivity of the GaN PD increased by approximately fifteen times and nine times, respectively, as the Au electrode ratio was changed from 1:2 to 1:20 under 302 nm illumination at 0 V. As a result, excellent responsivity and detectivity values of 8.51 A/W and 2.42 × 10¹³ Jones were achieved. Furthermore, all our GaN PDs exhibited excellent stability and repeatability under both 302 nm and 365 nm illumination conditions. In summary, GaN photodetectors with asymmetric Au electrode configurations stand out as promising candidates for future UVPD technologies due to their excellent performance and low-cost, straightforward fabrication.