A Solar-Blind Ultraviolet Photodetector with Self-Biasing Capability, Controlled by Surface Potential based on GaN Hexagonal Nano-Spikes

Abstract

In recent years, there’s been growing interest in developing solar-blind self-bias ultraviolet photodetectors for uses like monitoring extreme heat, enhancing security, and improving communications. Gallium-nitride (GaN), known for its ability to detect ultraviolet illumination, is a top choice for making these detectors. In this letter, we introduce a GaN photodetector designed with a hexagonal nano-spikes-like structure that enhances performance and allows it to operate without an external power source. We delve into how surface potential is pivotal in its self-biasing capability. This device shows remarkable performance, including a high responsitivity of 2100 mAW−1 and the ability to detect very weak-signals (4 femto-watts) under self-bias condition. Our findings pave the way to fabricate a GaN-based self-bias optoelectronic device.