Temperature dependence of current–voltage characteristics of Sn/p-GaTe Schottky diodes

The forward current–voltage (I–V) characteristics of Sn Schottky contacts on a Bridgman–Stockbarger grown p-GaTe layered semiconducting material have been measured over the temperature range of 80–300 K. Their analysis based on the thermionic emission (TE) mechanism has revealed an abnormal decrease of zero-bias barrier height and increase of ideality factor at lower temperatures. This behavior has been interpreted based on the assumption of a Gaussian distribution of barrier heights due to barrier height inhomogeneities that prevail at the interface. A Φb0 versus 1/T plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights, and values Φ̄b0(T=0)=0.89 eV and σ0=0.094 V for the mean barrier height and zero-bias S.D., respectively, have been obtained from this plot. Thus, a modified ln(Is/T2)−(q2σ02/2k2T2) versus 1/T plot gives Φ̄b0(T=0) and A∗∗ as 0.91 eV and 6.15 A K−2 cm−2, respectively. It can be concluded that the temperature dependence of I–V characteristics of the Schottky barrier on p-GaTe can be successfully explained on the basis of TE mechanism with Gaussian distribution of the barrier heights.