Enhancement of optical characteristic of InGaN/GaN multiple quantum-well structures by self-growing air voids

Abstract

InGaN/GaN multiple quantum-well (MQW) structures with a wavelength range of green were successfully grown on a c-plane GaN template with SiO 2 stripe patterns along the [11][12][13][14][15][16][17][18][19][20] and [1-100] directions as a mask. The surface morphologies of both samples were investigated using scanning electron microscopy and demonstrated anisotropic growth characteristics of GaN. The optical characteristics were investigated using Raman spectra and photoluminescence (PL). The InGaN/GaN MQW structure grown on the GaN template with SiO 2 stripes along the [1-100] orientation exhibited less stress and higher PL intensity. Transmission electron microscopy results indicated that portions of MQWs were grown on an inclined semipolar plane, and air voids occurred only when the direction of the mask stripe was along the [1-100] orientation. The enhancement of the optical characteristic was due to the air-void structure and inclined semipolar quantum-well sidewalls.InGaN/GaN MQWs, SiO 2 mask stripes, optical characteristic, inclined quantum-well sidewall, air voids

Application of nano-patterned InGaN fabricated by self-assembled Ni nano-masks in green InGaN/GaN multiple quantum wells

“…In addition, some efforts focus on the enhancement of light output. Useful techniques contain the use of patterned sapphire substrate (PSS) [13] , designing chip shape [14] , introducing air voids [15] , and roughening the p-GaN surface [16,17] . The point is to offer opportunity for the photons generated within MQWs to find the escape cone by multiple scattering.…”