The Gaussian distribution of barrier heights in Au/native fluoride/nHgCdTe Schottky diodes

Abstract

In this work the features of current transport through a barrier in Au/native fluoride/HgCdTe Schottky diode are under studying. Using I-V dependences at different (from 90 to 290 K) temperatures, it has been observed that an ideality factor decreases and a barrier height increases with a temperature increase what is in disagreement with the ideal thermionic emission theory of a Schottky barrier. The phenomenon assumed to be accounted for lateral non-uniformity of barrier heights at the metal/semiconductor interface. The Gaussian distribution is used to describe this inhomogeneity. Analysis of temperature I-V dependences allow us to conclude the double Gaussian distribution with the mean barrier heights of 0.5 eV and 0.67 eV and with the dispersions of 4.5 mV and 8.5 mV in 90-130 K and 130-270 K temperature ranges, respectively. With the Gaussian distribution taken into account, the Richardson constant value of 2 A/cm2K2 which is close to the theoretical one has been determined from I-V measurements.