Origins of the temperature dependence of the series resistance, ideality factor and barrier height based on the thermionic emission model for n-type GaN Schottky diodes

The temperature dependence of the series resistance (RS), ideality factor (η), and barrier height (ϕb) for n-type GaN Schottky diodes were studied. From the observed Hall-effect result, it is suggested that the increase of RS with increasing temperature may result from a decrease in electron mobility with increasing temperature and the increase in the effective density of states in the conduction band with increasing temperature may lead to an increase in the energy difference between the conduction band minimum and the Fermi level and a decrease in the probability of tunneling. It is shown that the tunneling behavior is responsible for decreasing ϕb and increasing η with decreasing temperature on the basis of the thermionic emission model.