It was shown that new data on the equilibrium As pressure over Ga-As melts resolved a discrepancy between published determinations of non-stoichiometry which had been obtained from titration and density/lattice parameter measurements. By analyzing data on donor solubility in crystals which had been grown from Ga-Bi solutions, experimental measurements of the concentration of charged Ga vacancies were obtained for the first time. This model of equilibrium dopant incorporation was shown to provide a much more satisfactory description than did the usually accepted concept of incorporation which was controlled by a Schottky barrier at the growth interface. Deduced values of the concentrations of the predominant point defects were used to construct the GaAs solidus.

D.T.J.Hurle: Materials Science Forum, 1995, 196-201, 179-88