Fabrication and photoluminescence studies of GaN nanopillars

GaN nanopillar arrays are fabricated by inductively coupled plasma reactive ion etching (ICP-RIE) of lithographically patterned GaN epilayers grown on sapphire substrate. The morphology and optical quality of the nanopillars is investigated by scanning electron microscopy (SEM) and micro-photoluminescence (μ-PL) respectively. The PL intensity of the nanopillars is enhanced by a factor of more than four compared to that of the epitaxial layers. However, a small increase in the full width half maximum (FWHM) of the nanopillar PL spectra is observed.