Analysis of temperature dependent current-voltage and capacitance-voltage characteristics of an Au/V2O5/n-Si Schottky diode

Abstract

Electronic properties of Au/V2O5/n-Si Schottky device have been investigated by temperature dependent current–voltage (I–V) and capacitance–voltage (C–V) measurements ranging from 300 K to 150 K. Ideality factor (n) and barrier height (ϕ) for the Schottky device were obtained from I–V characteristics as 2.04 and 0.83 eV at 300 K and 6.95 and 0.39 eV at 150 K respectively. It was observed that in presence of inhomogeneity at metal–semiconductor interface, the ideality factor increases and barrier height decreases with the decrease of temperature. The Richardson constant value was estimated as 137 A–cm−2–K−2 from modified Richardson plot, which is closer to the known theoretical value of n-Si where mean value of barrier height (ϕb0¯), and its standard deviation (σ0) were estimated using double Gaussian distribution (DGD) analysis. Different device parameters, namely, built-in potential, carrier concentration, image force lowering and depletion width were also obtained from the C–V–T measurements. First time use of V2O5 thin-film as an interfacial layer (IL) on Au/V2O5/n-Si Schottky diode was successfully explained by the thermionic emission (TE) theory. The interesting result obtained in this present work is the V2O5 thin-film reduced its conducting capability with decreasing temperature, while it shows a totally insulating behaviour below 150 K.