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

Abstract

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 Φ b0 versus 1/ T plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights, and values Φ ̄ b0 (T=0)=0.89 eV and σ 0=0.094 V for the mean barrier height and zero-bias S.D., respectively, have been obtained from this plot. Thus, a modified ln( I s/ T 2)−( q 2 σ 0 2/2 k 2 T 2) versus 1/ T plot gives Φ ̄ b0 (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.