Recent progress in GaN-based ultraviolet photodetectors Gallium nitride (GaN) materials, characterized by wide direct bandgap tunability, high photoelectronic efficiency and excellent chemical and thermal stability, have garnered significant attention for the development of GaN-based photoelectronic devices, including light-emitting diodes (LEDs), photodetectors and lasers. Photodetectors play a crucial role in both military and civilian applications.