Temperature-dependent electrical characteristics of CBD/CBD grown n-ZnO nanowire/p-Si heterojunction diodes

Heterojunction diodes are fabricated using a low-temperature chemical bath deposition of oriented and crystalline ZnO nanowires on a <1 1 1> p-silicon substrate. The electrical transport properties of the heterojunction are investigated at various temperatures by measuring current-voltage (I-V) characteristics in the range of 90-390 K. A thermionic emission (TE) model is used to analyze the transport behavior. The deviation in the experimental value of Richardson's constant for ZnO nanowires is obtained from I-V-T measurement. The temperature dependence of the effective barrier height and ideality factor is attributed to the inhomogeneous barrier height distribution at the n-ZnO NW/p-Si hetero-interface. The TE and barrier inhomogeneity model are simultaneously used to extract the appropriate value of the Richardson's constants in three different temperature regions. Linear fittings for three different temperature regions suggest multiple Gaussian distributions of barrier heights at the junction.