Fabrication and characterization of Al/n-Si/Al schottky diode with rGO interfacial layer obtained by using spin coating method

Abstract

In the present study, we investigated the optical and structural properties of reduced graphene oxide (rGO) thin film and some electrical properties of the Al/rGO/n-Si/Al heterojunction diode. Firstly, graphite oxide (GO) was synthesized by using the method of Hummers and Offeman. Subsequently, the reduction of GO was carried out with hydrazine hydrate by using a reflux system (at 100 ˚C for 18 hr). The rGO thin film was formed on n-type Si substrate through spin coating method and Al contacts were created to fabricate the diode. The absorption spectra of the thin film were taken in 200–500 nm wavelength range and the optical band gap of the film was found to be 3.65 eV. The morphological properties of the thin film formed on the n-Si substrate were analyzed by AFM and SEM. The electrical properties of Al/rGO/n-Si/Al diode were investigated using the current-voltage (I-V) measurements. The diode exhibited rectification behavior with the ideality factor (n) of 1.06 and the barrier height (Φb) of 0.72 eV at room temperature. In addition, I-V characteristics of the diode were examined as a function of temperature in the 80–300 K range. It was seen that the Φb and reverse saturation current (I0) values of the diode increased with increasing temperature, while the n values decreased. Furthermore, the electrical characteristic of Al/rGO/n-Si/Al were compared with Al/n-Si/Al junction too.