Electron traps in GaAs:Sb grown by liquid phase epitaxy

Abstract

Deep level transient spectroscopy studies of GaAs:Sb layers, grown by liquid phase epitaxy reveal the existence of two electron traps with activation energies of 0.4 and 0.54 eV. High temperature annealing of the material reduced the density of the former trap while that of the latter is increased substantially. Density of the 0.54 eV trap is also found to be controlled by the Sb content in the material. These two results, together with the obtained signature of the 0.54 eV trap, suggest that it is the same as the SbGa related electron trap observed previously in GaAs:Sb materials grown by other techniques. Annealing increases the density of this trap by creating more SbGa defects as a consequence of Ga out-diffusion from the material. Photocapacitance measurements indicate the presence of a 0.75 eV electron trap in the annealed layers, which is identified with the second charge state of the SbGa electron trap.