The effect of diffusion upon quantum-well structures was studied by using secondary ion mass spectrometry, Auger electron spectroscopy, capacitance-voltage measurements, photoluminescence, and X-ray diffraction methods. It was found that there was marked interdiffusion of Ga. In a multiple quantum well, Zn diffusion at 500C caused Ga intermixing and the Auger electron spectroscopic profiles became flat. At higher temperatures, an ordering was found such that the Ga concentration was greatest in the original InP layers. This was attributed to the effect of minimization of the free energy; balanced by an increase in the mismatch strain energy. Photoluminescence data revealed that interdiffusion began at temperatures above 420C.

G.J.Van Gurp, W.M.Van de Wijgert, G.M.Fontijn, P.J.A.Thijs: Journal of Applied Physics, 1990, 67[6], 2919-26