Self-Powered Photodetectors with Nickel-Doped ZnO Nanorods for Operation in Low-Light Environments

The development of next-generation optoelectronic devices relies on the necessity for self-powered, fast, and high-sensitivity photodetectors with a wide-spectral response. This Article investigates the impact of nickel doping on the growth of ZnO nanorods (79–123 nm diameter) on a p-type silicon substrate, exploring alterations in photovoltaic characteristics compared to the pure counterparts. The results reveal enhanced performances in devices with nickel doping ranging from 1% to 5%, exhibiting superior behavior across tested parameters. Despite consistent morphology and geometric aspects of the grown nanorods, the persistent presence of nickel was evident. Illumination from UV and visible light sources demonstrated increased current in I–V plots with rising doping levels, showcasing robust photovoltaic behavior at 0 V and enabling functionality as a self-powered photodetector. Under UV light, self-powered operation was observed at an intensity as low as 20 mW/cm 2, extending beyond 50 mW/cm 2 for visible light exposure. These devices exhibit applicability in detecting a broad spectrum of solar radiation, as evidenced by the influence of the wavelength and light intensity on the photocurrent response at zero bias. With pulsed frequencies of a 405 nm laser, changes in the photocurrent were observed with variations in operating frequency. Hence, a high-performance, wide spectral, self-powered photodetector capable of detecting minimal light intensity was fabricated.