Self-powered position-sensitive TiO2/PZT/p-GaN UV detector with long working distance

Position-sensitive photodetectors (PSDs) are crucial in applications such as target tracking, machine vision, and other fields that require precise spatial measurement. Conventional PSDs often face challenges in balancing long operating distances with high sensitivity. In this study, a self-powered, high-performance PSD with an extended operational range is developed. This enhancement was achieved by growing a PbZr_0.3Ti_0.7O₃ (PZT) film with strong polarization properties on a p-GaN substrate, utilizing the residual polarization field to modulate the Lateral Photovoltaic Effect (LPE) at the TiO₂/PZT/p-GaN heterojunction. The PSD demonstrates excellent photoresponse and sensitivity under ultraviolet (UV) illumination (365 nm). In the absence of an external electric field, a position sensitivity of 204 mV/mm is achieved when the PZT layer is transversely polarized at − 100 V. This represents a 128% increase compared to the device with the unpolarized PZT layer. This study presents an effective and straightforward approach for developing highly sensitive PSDs with extended working distances.