Enhanced diffusion in nonstoichiometric quantum wells and the decay of supersaturated vacancy concentrations

Abstract
Enhanced superlattice disordering in nonstoichiometric AlAs/GaAs quantum wells exhibits weak temperature dependence because of the decay of the supersaturated concentration of group-III vacancies. We present a formalism for transient enhanced diffusion in nonstoichiometric materials with which we can extract migration enthalpies Hm by assuming that the vacancy decay is thermally activated with an enthalpy Ha. By analyzing the electroabsorption from the quantum-confined Stark effect for a set of isochronal and isothermal anneals, we extract a migration enthalpy Hm=(1.8±0.2) eV for group-III vacancies, as well as an activation enthalpy Ha=(0.7±0.2) eV for vacancy annihilation.

This publication has 0 references indexed in Scilit: