Light Emission by Nanoporous GaN Produced by a Top-Down, Nonlithographical Nanopatterning

Abstract EN

Temperature-dependent photoluminescence (PL) spectroscopy is carried out to probe radiative recombination and related light emission processes in two-dimensional periodic close-packed nanopore arrays in gallium nitride (np-GaN).

The arrays were produced by nonlithographic nanopatterning of wurtzite GaN followed by a dry etching.

The results of Raman spectroscopy point to a small relaxation of the compressive stress of ~0.24 GPa in nanoporous vs.

bulk GaN.

At ~300 K, the PL emission is induced by excitons and not free-carrier interband radiative recombinations.

An evolution of the emission spectra with T is confirmed to be mainly a result of a decay of nonexcitonic PL emission and less of spectral shifts of the underlying PL bands.

A switching of excitonic PL regime observed experimentally was analyzed within the exciton recombination-generation framework.

The study provides new insights into the behaviors and physical mechanisms regulating light emission processes in np-GaN, critical to the development of nano-opto-electronic devices based on mesoscopic GaN.