Dark current analysis of p-i-n NiO/BiTiO3/ZnO thin film heterojunction diode

Abstract

Dark current analysis of fabricated NiO/BiTiO3/ZnO heterojunction thin film p-i-n diode is demonstrated in this paper. The diodes layers; p-type NiO, i-type BiTiO3 and n-type ZnO were fabricated by using a sol-gel method on glass substrates. This method is the most practical techniques used for manufacturing the nanostructured thin films of metal oxide and perovskite semiconductors. The electrical characteristics of the vertical p-i-n diode were investigated using current-voltage characterization at room ambient in dark condition. The parameters, for example, threshold voltage, rectifying ratio, ideality factor, junction resistance and leakage current, were extracted from the measured data. The turn on voltage, ideality factor, saturation current, junction series resistance, and junction shunt resistance were estimated to be 0.6 V, 6.1, 8×10-7 A, 40 Ω and 760 Ω, respectively. The effect of post-fabrication heat treatments on electrical properties has been studied. The optimum temperature at 100°C that improves the device performance. The performance enhancement attributed to the interface improvement of the between the aluminum contact and p-i-n thin films. With respect as-deposited p-i-n devices, the heat-treated diodes performance parameters such as threshold voltage, ideality factor and leakage current of devices are found to improve by 5%, 47.3%, and 63.3%, respectively. The rectification performance of the device was 13.6 at 100°C and degrades after the temperature reached 125°C attributed to new material phases appears at interfaces.