Abstract
In the planer technology, the photoconduction response is greatly affected by the surface recombination phenomenon. The influence of surface defects on detection capabilities of photoconductors infrared detectors is analyzed. A model based on surface states associated of surface defects is also developed. In this model, the barrier height at the semiconductor free surface is modified under photonic excitation .The procedure used for calculation of such parameter has taken into account the depletion region and the influence of the photon wavelength (lambda). The recombination of carriers at the semiconductor surface is also examined within the Shockley-Read-Hall theory. In a self-consistent way, the continuity equation is solved in order to obtain excess carriers density and also to deduce quantum efficiency, gain and responsivity as function of the wavelength. Numerical results obtained by the present approach model are in good agreement with the published experimental results for case p-PbS.