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

Abstract

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 ΦB0, 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 and a standard deviation of σs0 = 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, ln(I0/T2) − (q2σ2s0/2k2T2) versus 103/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.