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 Phi(b0) versus 1/T plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights, and values (Phi) over bar (b0) (T = 0) = 0.89 eV and sigma(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)sigma(0)(2)/2k(2)T(2)) versus 1/T plot gives (Phi) over bar (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. (C) 2003 Elsevier Science B.V. All rights reserved.