Water-enabled enhancement of transparent Schottky photodetectors

Abstract

Photodetectors (PDs) are essential optoelectronic devices known for their high photoelectric conversion efficiency. Accordingly, they are widely utilized in sensing, optical communication, smart windows, and security systems. This study presents a transparent Schottky PDs enhanced by a water layer on a glass/indium tin oxide (ITO)/ZnO/Ag(O)/aluminum-doped zinc oxide (AZO) structure. The water layer acts as an index-matching medium, reducing Fresnel reflection at the device surface and increasing light transmission into the PDs. Additionally, electric double layer (EDL) formation at the Ag(O)/water interface amplifies the local electric field, promoting efficient separation and collection of photogenerated carriers. The modification results in transparency enhancements of approximately 6.25% and photocurrent improvements of 20–25% across the ultraviolet-to-visible spectrum (365–623 nm) under various light intensities (0.04–2.4 mW cm⁻²) relative to the devices without the water layer. Overall, these findings position the underwater glass/ITO/ZnO/Ag(O)/AZO PD as an innovative, energy-efficient platform featuring a broad spectral response and wide field-of-view (wFoV) capabilities. Thus, underwater engineering can be applied in a facile and effective manner to develop transparent, self-powered PDs, thereby unlocking new opportunities for advancing safe and sustainable water-related optoelectronic technologies.