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 re actor operating at atmospheric pressure on (0 0 0 1) oriented sapphire. A s tudy 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 rati o, and it was largely influenced by the parasitic reactions in the gas phas e. The yellow band intensity was depressed when the parasitic reactions wer e reduced. We also observed that the growth rate of GaN : Si films was infl uenced by the Si doping and the parasitic reactions. The growth rate decrea sed with the increase of SiH4/TMGa ratio and was larger in larger parasitic reactions reactor. Si-doped GaN films with carrier concentration of 2 x 10 (19) cm(-3), electron mobility of 120 cm(2)/Vs, FWHM of the bandedge emissi on of only 60 meV at room temperature, and no yellow emission were obtained . (C) 2001 Elsevier Science B.V. All rights reserved.