Phase transition induced double-Gaussian barrier height distribution in Schottky diode

The charge transport mechanisms of Hg contact on n-type silicon crystal having 〈1 0 0〉 orientation were investigated in the temperature range of 160–293 K by the thermionic emission theory. The temperature variation of barrier height and ideality factor illustrates an inhomogeneous interface with a Gaussian barrier height distribution. The plots of temperature dependent zero-bias barrier height, ideality factor, series resistance and reverse leakage current show a discontinuity below 240 K. The experimental barrier height and ideality factor versus 1/T plot gives two slopes, one in the 160–220 K region and the other in the 240–293 K region, thereby revealing a double Gaussian distribution of barrier heights. The observed discontinuity in the diode parameters and the existence of double Gaussian barrier heights are interpreted on the basis of phase transition of mercury from its liquid state to solid form.