Fabrication and photo-voltaic measurements of a 210-nm-period GaN-based surface nano-structure photodetector

In this study, Nanostructure devices were fabricated from the wafer with LED structure grown by metal organic chemical vapor deposition (MOCVD). A GaN-based nanostructure photodetector has been made using nanoimprint lithography (NIL) and reactive ion etching (RIE). The nanopattern is regular triangles consisting of columns, whose diameter and pitch are 100 and 200 nm, respectively. Around 66 nm heights of nano-columns were formed by changing the etching time of RIE. The photovoltage between p- and n-layer took on 6 or 12 periodes when changing the incident angle of illumination based on the nano-surface or on the back side. Using the character, this type of photodetector can find out the change of incidence angle or the change of wavelength of incident light.