High optical quality GaN nanopillar arrays

Abstract

GaN nanopillar arrays have been fabricated by inductively coupled plasma etching of GaN films using anodic aluminum oxide film as an etch mask. The average diameter and length of these pillars are 60–65nm and 350–400nm, respectively. Ultraviolet microphotoluminescence measurements indicate high photoluminescence intensity and stress relaxation in these GaN nanopillars as compared to the starting epitaxial GaN films. Evidence of good crystalline quality is also observed by micro-Raman measurements, wherein a redshift of the E2high mode from GaN nanopillars suggests partial relaxation of the compressive strain. In addition, breakdown of the polarization selection rules led to the appearance of symmetry-forbidden and quasipolar modes.

Synthesis, optical properties and growth mechanism of leaf-like GaN crystal

“…The near-band-edge emission at 369 nm was observed, while the well-known yellow band emission was not observed. The similar PL result was also reported in a dislocation-free GaN nanopillar grown on Si(1 1 1) by a hot-wall epitaxy technique [17]. Such PL result again indicates the high quality of as-prepared GaN druse crystals.…”

GaN nanowire fabricated by selective wet-etching of GaN micro truncated-pyramid

“…But there is still a challenge to grow uniform GaN NWs with diameter of a few tens of nanometer by this method. Recently, masked lithography has been carried out to produce well-controlled GaN NWs arrays from GaN film [24][25][26]. However, lithographic etching induced surface damage will influence the crystal quality.…”

Strain relaxation and quantum confinement in InGaN/GaN nanoposts

“…A certain effect of 3D quantum confinement was observed at a low temperature. Meanwhile, by using anodic aluminium oxide nanoparticles as the etching mask and inductively coupled plasma reactive ion etching (ICP RIE), GaN nanoposts around 60 nm in size were produced [3]. Strain relaxation in such a structure was observed through microphotoluminescence and micro-Raman spectroscopy measurements.…”