Fabrication of high aspect ratio gallium nitride nanostructures by photochemical etching for enhanced photocurrent and photoluminescence property

High aspect ratio gallium nitride (GaN) nanostructures were fabricated by photochemical etching using hydrofluoric acid as the etchant. Under the etching time of 20 min, the surface pore density is estimated to be ~ 5.6 × 10⁹ cm², and the aspect ratio of the pore structure is as high as ~ 10: 1. The biggest photocurrent and strongest photoluminescence intensity of the etched GaN are ~ 3.2 and 9.7 times of that of the as-grown GaN, respectively, which demonstrates high aspect ratio GaN nanostructures have great potential for a series of photoelectric and optical devices.