Simple analytical expressions were derived for the approximate estimation of the interdiffusion coefficient, of partially disordered quantum-well heterostructures, directly from measurements of the photoluminescence phase shift which was associated with layer interdiffusion. The phase shift was calculated as a function of the interdiffusion length, (Dt)½, in the lattice-matched system, GaAs/Ga0.7Al0.3As. The calculations were performed within the framework of the envelope function approximation and Fick's law. A simple relationship was derived for the variation in phase shift as a function of the dimensionless parameter, (Dt)½/L, where L was the quantum-well thickness. This satisfactorily accounted for most of the published interdiffusivity values, to within a factor of 2.

M.T.Furtado, M.S.S.Loural: Superlattices and Microstructures, 1993, 14[1], 21-5