On the difference in the apparent barrier height of inhomogeneous Schottky diodes with a Gaussian distribution

Abstract

The differences in the calculated apparent Schottky barrier heights as obtained from different approaches assuming a Gaussian distribution model of barrier potential are discussed. A modified theoretical expression for the saturation current and consequently a new expression for the apparent barrier height, evaluated numerically, are proposed. The current–voltage (I–V) expression obtained is subsequently used to generate I–V curves. An adequate genetic algorithm has been used to extract diode parameters. While the previous approaches used may lead to an unphysical negative apparent barrier height at low temperatures, or may suggest the existence of a lowest critical temperature up to which the apparent barrier height can be calculated, our approach presented here yields results for the apparent barrier height in good agreement with the extracted values at different temperatures. Therefore, it is concluded that the temperature dependence of the apparent Schottky barrier height can be successfully explained with the presently proposed approach, the detailed aspects of which are presented in this contribution.