Effect of the silicon doping concentration on the recombination kinetics of DX centers in Al_0.35Ga_0.65As

The recombination (electron capture) kinetics of the ionized DX center in AlxGa1-xAs have been measured as a function of temperature and silicon doping concentration. It is shown that for x≅0.35, the silicon concentration dependence of the recombination kinetics is dominated by effects of the electron distribution in the conduction band, and is insensitive to changes in the trap characteristics. In a model kinetic calculation consistent with the data the trap is found to capture through a level 0.202 eV from the bottom of the conduction band with a width of 0.045 eV, independent of DX center concentration.