Liquid-phase epitaxial layers were studied by using a diffusion source which contained GaS and As in a mass ratio of 2:1. The diffusion of S was carried out in a sealed quartz ampoule at 820C, and in ambient As at a vapour pressure of 1atm. The diffusion data could be described by:

D (cm2/s) = 1.6 x 109 exp[-4.7(eV)/kT]

H.Nishi, Y.Horikoshi, H.Ito: Journal of Applied Physics, 1998, 84[10], 5811-3