Effect of inhomogeneous Schottky barrier height of SnO2 nanowires device

Abstract: The current–voltage (I–V) characteristics of metal–semiconductor junction (Au–Ni/SnO₂/Au–Ni) Schottky barrier in SnO₂ nanowires were investigated over a wide temperature range. By using the Schottky–Mott model, the zero bias barrier height Φ_Bwas estimated from I–V characteristics, and it was found to increase with increasing temperature; on the other hand the ideality factor (n) was found to decrease with increasing temperature. The variation in the Schottky barrier and n was attributed to the spatial inhomogeneity of the Schottky barrier height. The experimental I–Vcharacteristics exhibited a Gaussian distribution having mean barrier heights ${\overline{{\rm{\Phi }}}}_{B}$ of 0.30 eV and standard deviation σ _sof 60 meV. Additionally, the Richardson modified constant was obtained to be 70 A cm⁻² K⁻², leading to an effective mass of 0.58m ₀. Consequently, the temperature dependence of I–V characteristics of the SnO₂ nanowire devices can be successfully explained on the Schottky–Mott theory framework taking into account a Gaussian distribution of barrier heights.