It was noted that enhanced superlattice disordering in non-stoichiometric quantum wells exhibited a weak temperature dependence because of a decay of the supersaturated concentration of group-III vacancies. A formalism was presented for transient enhanced diffusion in non-stoichiometric materials. The migration enthalpy could be deduced from this by assuming that the vacancy decay was thermally activated. By analyzing electro-absorption from the quantum-confined Stark effect for a set of isochronal and isothermal annealing treatments, it was possible to extract a migration enthalpy of 1.8eV for group-III vacancies as well as an activation enthalpy of 0.7eV for vacancy annihilation.

I.Lahiri, D.D.Nolte, M.R.Melloch, J.M.Woodall, W.Walukiewicz: Applied Physics Letters, 1996, 69[2], 239-41