The effect of pressure and stoichiometry upon the Al-Ga interdiffusion of undoped multiple quantum wells was investigated over the entire composition range of tile GaAs solidus. The occurrence of a two orders of magnitude increase in the interdiffusion coefficient suggested that interdiffusion in an intrinsic crystal was mediated mainly by column-III vacancies over the whole solidus range. It was noted that the photoluminescence intensity of the Ga-rich crystal was more than 3 orders of magnitude greater than that of the As-rich crystal.

B.L.Olmsted, S.N.Houde-Walter: Applied Physics Letters, 1992, 60[3], 368-70