GaN epilayers and AlGaN/GaN multiple quantum wells grown on freestading 1100 oriented GaN substrates

摘要

We report on the homoepitaxial growth of GaN on freestanding [1100] oriented GaN substrates using metalorganic chemical vapor deposition.A proper pretreatment of growth conditions such as V/III molar-ratio and temperature on the surface morphology and optical properties of epilayers was investigated.Optimized pretreatment and growth conditions led to high quality [1100] oriented GaN epilayers with a smooth surface morphology and strong band-edge emission.These layers also exhibited strong room temperature stimulated emission under high intensity pulsed optical pumping.Based on these GaN epilayer.AlGaN/GaN multiple quantum wells have been grown on the freestanding M-plane GaN.Photoluminescence data confirm that built-in electric field for M-plane structures is very weak,and this situation results in a stronger PL intensity in comprison with C-plane multiple quantum wells in tests at low excitation level.