Growth and characterization of m-plane GaN-based layers on LiAlO2 (1Â 0Â 0) grown by MOVPE

We study the growth and properties of m-plane InGaN/GaN structure on LiAlO2 substrate grown by metal organic vapor phase epitaxy. Surface nitridation of LiAlO2 substrate is employed as the first step. A buffer structure consisting of InGaN:Mg and GaN layers was deposited prior to the active layer growth. The X-ray diffraction shows the growth is in the m-plane direction. The transmission electron microscopy results demonstrate that the density of the dislocations can be reduced substantially in the GaN buffer layer grown at high temperature. We found that optical emission is not influenced by the polarization-induced electric field from the photoluminescence measurements with different excitation densities. Moreover, the spontaneous emission displays strong in-plane polarization anisotropy, which can be attributed to the anisotropic biaxial strain. Our approach hints a promising way to realize high-efficient GaN-based light-emitting devices.