Current transport and its effect on the determination of the Schottky-barrier height in a typical system: Gold on silicon

Abstract

The measurements of photovoltage, internal photoemission, current-voltage (I-V) and capacitance-voltage (C-V) have been performed for Au on n-Si (111) within a temperature range of 7 to 300 K. The values of Schottky-barrier height at room temperature obtained from these four measurements are in very good agreement, but conflicting results have been obtained at low temperatures. The measurements of both the internal photoemission and the C-V show a negative temperature dependence of the barrier height which is almost identical to that of the indirect energy band gap in silicon, but the barrier height obtained from the photovoltage measurements and the I-V measurements strongly decreases as temperature decreases. In this paper, the influence of the current transport on the determination of the Schottky-barrier height is discussed, and it is demonstrated that the conflicting results may be explained well in terms of the recombination current involved in the photovoltage measurements and the I-V measurements.