Growth and characterization of thick GaN by sublimation method and homoepitaxial growth by metalorganic chemical vapor deposition

Thick GaN, 10-30 mu m, was grown on sapphire substrate by a sublimation method for the first time. GaN was homoepitaxially grown on this thick layer by metalorganic chemical vapor deposition to obtain a high-quality layer. Stimulated emission from a photopumped homoepitaxial GaN grown on thick GaN prepared by the sublimation method at room temperature was demonstrated. The threshold of the stimulated emission was estimated to be 1.04 MW/cm(2).