The homo-epitaxial growth of GaInN/GaN-based light emitting diodes on quasi-bulk GaN with an atomically flat polished surface was demonstrated. The threading dislocation densities of the epitaxial layers were 2–5×108/cm2 which was one order of magnitude less than those grown on c-plane sapphire substrate. The growth defects introduced during the epitaxial process were also one order of magnitude smaller than those grown on the sapphire substrate. The crystalline quality and the optical properties of the epitaxial layer and device performance were much improved. The optical output power of the light emitting diode increased by more than one order of magnitude compared to those on sapphire substrate.

Dislocation Analysis in Homoepitaxial GaInN/GaN Light Emitting Diode Growth. T.Detchprohm, Y.Xia, Y.Xi, M.Zhu, W.Zhao, Y.Li, E.F.Schubert, L.Liu, D.Tsvetkov, D.Hanser, C.Wetzel: Journal of Crystal Growth, 2007, 298, 272-5