Carrier transport mechanism of Se/n-type Si Schottky diodes

The carrier transport mechanism of Se Schottky contacts to an n-type Si substrate were investigated using current–voltage (I–V) and capacitance–voltage (C–V) characteristics. The barrier height and ideality factor measured from the forward bias I–V characteristics were 0.72 eV and 1.2, respectively. A nearly identical barrier height was extracted with the Norde method. However, the C–V characteristics revealed a barrier height of 0.91 eV. The relatively large discrepancy between the Schottky barrier heights measured from the I–V and C–V characteristics could be attributed to the inhomogeneity of the barrier heights across the contact. Thermionic emission dominated the current conduction mechanism in the forward bias region. The primary process involved in the leakage current could be associated with lowering of the Schottky barrier in which the carriers were emitted over the potential barrier by the absorption of thermal energy.

► We investigated carrier transport mechanism of Se/n-type Si Schottky diodes.
► Inhomogeneity of Schottky barrier heights across the contact.
► Thermionic emission dominated the forward-bias conduction mechanism.
► Leakage current could be associated with lowering of the Schottky barrier.