Plasma-assisted MBE growth of GaN and InGaN on different substrates

Abstract We investigate structural and optical properties of GaN and InGaN on sapphire and neodymium gallate substrates, deposited by MBE using a novel RF and conventional ECR nitrogen activators. The GaN/NdGaO 3 layer demonstrates higher luminescence efficiency compared with GaN/Al 2 O 3 . Dislocation density in GaN/NdGaO 3 , estimated using X-ray diffraction measurements, is much less than that in the layers on sapphire substrate (the dominant vertical screw dislocation density is 10 4 or less). The layers demonstrate a direct correlation between the dislocation density and incorporation of oxygen and other contaminations determined by secondary ion mass spectroscopy measurements, with the lowest impurity concentration located in the GaN/NdGaO 3 epilayers. All the layers grown by the novel nitrogen source exhibit negligible yellow photoluminescence band independently of the substrate type.