Effects of Variation of Temperature on the Radiative Recombination in a Thin film of Gallium Antimonide (GaSb)

Abstract

In this study, the effects of temperature on the radiative recombination of Gallium Antimonide (GaSb) thin film semiconductor are investigated. First, using the illumination mechanism, the photon absorption rate as a function of the depth below the illuminated surface in both the bulk and the thin films of GaSb were determined at different temperature. Then, the depths below illuminated surface dependence of the low injection level thermal equilibrium carrier concentrations in a thin film of Gallium Antimonide (GaSb) at different temperature were investigated by considering the variation of the energy bending at the surface. Finally, using the steady state condition of the free carrier’s generation recombination mechanism, the radiative excess carrier lifetime of the photo-generated free carriers is described in both thin films and the bulk material as function of the depth below the illuminated surface at different temperatures and injection levels. The obtained result indicates that, photon absorption rate and the free carrier’s generation rate in general increases with decreasing the thickness of the thin films and the variation of the absorption rate with the thicknesses of the samples is high for high temperatures. The photo-response of the thin film semiconductor is in general found to be dominated by the property of the surface depletion layers of the material and hence extremely higher than the photo response of the deep bulk.