High-Sensitivity DTSs Based on Diamond with a Low Doping Drift Layer

Temperature monitoring is considerably important during the operation of power devices. Herein, pseudo-vertical diamond Schottky diodes with a low-doped drift layer were fabricated as diode temperature sensors (DTSs). The current-voltage characteristics determined in the range of 298-664 K revealed an increase in the forward current with increasing temperature. The sensing ability of the as-fabricated sensors was evaluated by characterizing the temperature dependence of the forward voltage drop at certain currents. In this study, the highest sensitivity was obtained for a DTS based on the wide bandgap semiconductor. However, the obtained sensitivities exhibited different values in high-and low-temperature ranges for the currents of 10-5, 10-4, and 10-3 A. To explain the sectional sensitivities, theoretical models were proposed based on the thermionic emission (TE) model and Cheung's model. The results indicated the presence of an inhomogeneous Schottky contact and a temperature-dependent series resistance, which explained the sectional and ultrahigh sensitivities.