The incorporation of Si into VGF-grown GaAs was examined by Hall effect measurements, spark source mass spectrometry and photoluminescence . It was found that the Si was incorporated into the crystal according to Scheils-law with a Si
concentration increase from 1.5 x 1018 to 1019/cm3. It was found that the intensity of the photoluminescence peak with energy close to the band gap decreases with increasing Si content of the material, whereas the intensity of the photoluminescence peak related to the acceptor SiGaVGa showed opposite behaviour. A compensation model which takes into account the acceptors SiAs and SiGaVGa was developed. The model describes the relationship between Si concentration and the charge carrier concentration up to Si concentrations of 1019/cm3 in GaAs grown under low thermal gradients.

Analysis of Silicon Incorporation into VGF-Grown GaAs. B.Birkmann, R.Weingärtner, P.Wellmann, B.Wiedemann, G.Müller: Journal of Crystal Growth, 2002, 237-239, 345-9