The fabrication of Al-pSnSe Schottky diodes and the temperature dependence of I-V characteristics in the temperature range 60 < T < 330 K have been studied. A decrease in the experimental barrier height Φap and an increase in the ideality factor n with a decrease in temperature have been explained based on barrier height inhomogeneities at the metal-semiconductor interface. It is proven that the presence of a distribution of barrier heights is responsible for the apparent decrease of the zero-bias barrier height. The voltage dependence of the standard deviation causes the increase of ideality factor at low temperatures. The mean barrier height Φbmean = 0.851 eV and the Richardson constant A* = 10.26 A cm−2 K−2 have been calculated by means of the modified Richardson plot. The value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights with that of the theoretical value.