An experimental study for thermal sensing applications of PP and PN heterojunctions fabricated in the same architecture and under the same conditions

Abstract

In this research, Ni/p-GO@Fe3O4/p-Si (P–P) and Ni/ p-GO@Fe3O4/n-Si (P–N) heterojunctions (HJs) were constructed under the same conditions. Current–voltage (I–V) measurements of devices over a wide temperature range were investigated. Thermionic emission theory was used to evaluate the temperature-dependent I–V characteristics. The ideality factor (n), barrier height (Φ), rectification ratio (RR) and turn-on voltage (V 0), which are the main HJ parameters of the HJs, were determined as a function of temperature and it was seen that all parameters were dependent on temperature. The n, RR, and V 0 values for both devices decreased with increasing temperature, while Φ increased. This was attributed to the inhomogeneity between p-GO@Fe3O4 and Si. The thermal sensitivity (S) and activation energy of both devices were calculated and it was seen that S decreased linearly with increasing current. Furthermore, the highest sensitivity and the lowest activation energy values were determined as 1.35 mV K−1 and 0.79 eV, respectively for P–P HJ. These values were calculated as 0.97 mV K−1 and 0.66 eV for P–N HJ, respectively.