Van der Waals epitaxy GaN on fluorophlogopite mica for transfer-free flexible UV photodetector

GaN thin films have been deposited on flexible and high-temperature-resistant fluorophlogopite mica (F-mica) substrates by molecular beam epitaxy. The in-plane epitaxial relationship between GaN and F-mica has been proved to be GaN[11-20]//F-mica[010]. Subsequently, graphene was transferred onto the GaN thin films to serve as a transparent electrode for the fabrication of ultraviolet detectors, and 0.3 A/W responsivity was measured at -1 V under 365 nm ultraviolet illumination with an intensity of 0.1 mW/cm2. Meanwhile, after multiple bending cycles, the crystalline structure of GaN and the photocurrents of the devices remained stable.