A GaN Nanowire-Based Photodetector With Ag Nanowires as Transparent Electrodes

The fabrication and the characterization of a fully nanowire-based UV photodetector are reported. The photodetector consists of the transparent top electrode of very-long Ag nanowires and the active region of GaN nanowires. The photocurrent increases by 1400 times when the photodetector is illuminated by a xenon lamp, attributing to the high crystal quality of GaN nanowires and the Schottky contact of GaN nanowires with Ag nanowires. The adsorbed molecules and the dangling bonds on the surface of the GaN nanowires increase the recombination rate of photogenerated holes and shorten the photoresponse time of the photodetector in air than those in vacuum. The detector is most responsive at 350 nm, but shows less sensitivity to a wavelength around 300 nm due to the absorption of Ag nanowires.