New aspects of the temperature dependence of the current in inhomogeneous Schottky diodes

Recently, some peculiarities of current–voltage ( I – V ) curves of inhomogeneous diodes at low temperatures, which appear not to be in accordance with the concept of thermionic theory, have been discussed in the literature. We have recalculated some of the published results by a direct numerical iteration of I – V curves without an approximation of the apparent barrier height. We have confirmed that the discrepancy connected with the saturation current can be removed by lowering the integration limit for the apparent barrier calculation. It is further shown that the currently used formula for the apparent barrier height with integration limits −∞ and ∞ may lead to an unphysical negative apparent barrier height. We have also shown that the crossing of low-temperature I – V curves with higher-temperature curves is not the result of the difference in ideality factors for single curves but it is caused by the different apparent barrier heights at different temperatures. The ideality factor of these inhomogeneous diodes remains unity, just as the ideality factor of single diode patches creating the diode, and there is no need to generate I – V curves with artificially deteriorated ideality factors at lower temperatures.