The volt-ampere characteristic of a metal-semiconductor junction of small area,with the assumptions of diffusion theory

A metal-semiconductor junction was considered on the assumptions of diffusion theory, taking into account the presence of a gap between the metal and the semiconductor. A junction was chosen of area small enough for it to be possible to neglect the decrease due to recombination relative to the decrease due to divergence of the lines of flow. The volt-ampere characteristics and dependences of the injection coefficient on the voltage were obtained for the cases of low and high injection levels and slight or considerable band bending. It was shown that in all the cases indicated the nature of the dependence of the injection coefficient on the voltage (increasing or decreasing) depends essentially on the distribution of the voltage drop between the gap and the space charge region. Given certain relationships between the parameters of the semiconductor the latter dependence can take the form of a curve with a maximum.