Hydrostatic pressure dependence of interface state density of Cd/n-type GaAs Schottky barrier diodes

The interface state density obtained from current–voltage (I–V) characteristics of Cd/n-type GaAs Schottky barrier diodes (SBDs) at room temperature under hydrostatic pressure was investigated. SBD parameters such as ideality factor (n), series resistance (Rs), and barrier height (φb), were obtained from I–V measurements using Cheung's method. The diode parameters, such as ideality factor, series resistance, and barrier heights, were found in the range of 1.464–1.474, 0.995–4.359 kΩ and 0.739–0.777 eV, respectively, with sweeping pressure. The diode shows non-ideal I–V behaviors with an ideality factor greater than unity. Additionally, the energy distribution of interface state density was determined from the forward bias I–V characteristics by taking into account the bias dependence of the effective barrier height. The results have shown that the presence of the interfacial native oxide layer between the metal and the semiconductor seriously affects interface state density under hydrostatic pressure.