Growth of GaN single crystals and properties of homoepitaxial MOCVD layers

Recently high quality GaN plates have been grown from the solution in liquid gallium at N/sub 2/ pressure up to 20 kbar and temperature close to 1600/spl deg/C. These single crystals have been used as substrates for homoepitaxial growth of GaN layer by MOCVD. The influence of the polarity of the Ga or N terminated surface of the substrate on the quality of the homoepitaxial layer is discussed. The structural and optical properties of homoepitaxial layers are presented and discussed.