High Optical Quality Nanoporous GaN Prepared by Photoelectrochemical Etching
Author(s)Vajpeyi, Agam P.; Chua, Soo-Jin; Tripathy, S.; Fitzgerald, Eugene A.
Nanoporous GaN films are prepared by UV assisted electrochemical etching using HF solution as an electrolyte. To assess the optical quality and morphology of these nanoporous films, micro-photoluminescence (PL), micro-Raman scattering, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques have been employed. SEM and AFM measurements revealed an average pore size of about 85-90 nm with a transverse dimension of 70-75 nm. As compared to the as-grown GaN film, the porous layer exhibits a substantial photoluminescence intensity enhancement with a partial relaxation of compressive stress. Such a stress relaxation is further confirmed by the red shifted E₂(TO) phonon peak in the Raman spectrum of porous GaN.
Advanced Materials for Micro- and Nano-Systems (AMMNS);
gallium nitride, porous semiconductors, ultraviolet assisted electrochemical etching, nanoporous GaN film