Temperature-dependent barrier characteristics of Ag/p-SnS Schottky barrier diodes

The current-voltage (I-V) characteristics of Ag/p-SnS Schottky barrier diodes were measured in the temperature range of 100-300 K and have been interpreted on the basis of the assumption of a Gaussian distribution of barrier heights (BHs) due to barrier height inhomogeneities that prevail at the interface. It is shown that the occurrence of a Gaussian distribution of the BHs is responsible for the decrease of the apparent barrier height Phi(B0), increase of the ideality factor n and nonlinearity in the activation energy plot at low temperatures. The inhomogeneities are considered to have a Gaussian distribution with a mean barrier height of (Phi) over bar (b0) = 0.649 eV and a standard deviation of sigma(s0) = 0.093 V at zero bias. Furthermore, the mean barrier height and the Richardson constant values were obtained as 0.642 eV and 12.89 A K-2 cm(-2), respectively, by means of the modified Richardson plot, In(I-0/ T-2) - (q(2)sigma(s0)(2)/2k(2)T(2)) versus 10(3)/T. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Schottky barrier on p-type SnS can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.