The influence of Si-doping to the growth rate and yellow luminescence of GaN grown by MOCVD

The growth of Si-doped GaN films was performed by MOCVD using a homemade reactor operating at atmospheric pressure on (0 0 0 1) oriented sapphire. A study of the effect of Si-doping indicated that the intensity of yellow band emission in GaN : Si films decreased with the increasing of SiH4/TMGa ratio, and it was largely influenced by the parasitic reactions in the gas phase. The yellow band intensity was depressed when the parasitic reactions were reduced. We also observed that the growth rate of GaN : Si films was influenced by the Si doping and the parasitic reactions. The growth rate decreased with the increase of SiH4/TMGa ratio and was larger in larger parasitic reactions reactor. Si-doped GaN films with carrier concentration of 2×1019 cm−3, electron mobility of 120 cm2/V s, FWHM of the band-edge emission of only 60 meV at room temperature, and no yellow emission were obtained.