Visible-blind photodetector based on p–i–n junction GaN nanowire ensembles

Abstract

We report the synthesis, fabrication and extensive characterization of a visible-blindphotodetector based on p–i–n junction GaN nanowire ensembles. The nanowireswere grown by plasma-assisted molecular beam epitaxy on an n-doped Si(111)substrate, encapsulated into a spin-on-glass and processed using dry etching andmetallization techniques. The detector presents a high peak responsivity of0.47 A W − 1 at − 1 V.The spectral response of the detector is restricted to the UV range with a UV-to-visible rejection ratioof 2 × 102. The dependence on the incident power and the operation speed of the photodetector arediscussed.