Frequency-Dependent Electrical Characterization of GO-SiO2 Composites in a Schottky Device

Abstract

An Al/GO-SiO2/p-Si device was obtained via the spin coating technique for the GO-SiO2 interfacial composite layer, and the thermal evaporation technique was employed for Al contacts. The device was subsequently analyzed via impedance spectroscopy for on a wide range of frequency (from 10 kHz to 5 MHz) and voltage (± 1 V) at room temperature. Main electrical parameters including barrier height, series resistance, doping concentration and interface states of the device were calculated using C–V and G–V characteristics. According to the C–V and G–V characteristics, the main electrical parameters were affected by the series resistance and interface states. The device exhibited negative capacitances, and the capacitance and conductance values were found to be a strong function of the frequency and voltage. The Al/GO-SiO2/p-Si device was also characterized via dielectric characterization. The profiles of ε′,ε″ tan δ, M′M″ and σ in relation to frequency and voltage were plotted and are discussed in details. All the dielectric parameters were found to be a strong function of frequency and voltage, and the interface states were more effective at low frequencies for this device. Instead of using only a SiO2 layer in the interface, a GO-SiO2 composite structure can be used as a new material for more effective metal–oxide–semiconductor (MOS) devices. © 2018, The Minerals, Metals & Materials Society.