Temperature-dependent electrical properties for graphene Schottky contact on n-type Si with and without sulfide treatment

The temperature-dependent current–voltage (I–V) characteristics of graphene/n-type Si Schottky diodes with and without sulfide treatment were measured in the temperature range of 150–420 K. The temperature dependence of forward-bias I–V characteristics can be explained on the basis of the thermionic emission theory by assuming the presence of Gaussian distribution of the barrier heights. The graphene/n-type Si device with sulfide treatment exhibits a good rectifying behavior with the ideality factor of 1.8 and low leakage at 300 K. The enhanced device performance is considered to mainly come from the presence of Si–S bonds that serve to improve the Schottky barrier inhomogeneity. Compared to the fitting data for the temperature-dependent reverse-bias I–V characteristics of graphene/n-type Si devices without sulfide treatment, the fitting data for the temperature-dependent reverse-bias I–V characteristics of graphene/n-type Si devices with sulfide treatment show that a higher barrier height for hopping result in a lower leakage current. This is because of more homogenous barrier height for graphene/n-type Si devices with sulfide treatment.