Investigations on Strained AlGaN/GaN/Sapphire and GaInN Multi-Quantum-Well Surface LEDs Using AlGaN/GaN Bragg Reflectors

摘要

Investigations were carried out on metalorganic- chemical-vapor-deposition (MOCVD)-grown strained AlGaN/ GaN/sapphire structures using X-ray diffratometry. While Al- GaN with lower AlN molar fraction (<0.1) is under the in-plane compressive stress, it is under the in-plane tensile stress with high AlN molar fraction (>0.1). Thought tensile stress caused the cracks in AlGaN layer with high AlN molar fraction, we found that the cracks dramatically reduced when the GaN layer qual- ity was not good.