A comparison of electrical characteristics of the Au/n-Si Schottky diodes with (ZnCdS:GO(1:1) and (ZnCdS:GO(1:0.5) doped PVP interlayer using current–voltage (I–V) and impedance–voltage (Z–V) measurements

In this study, both the Au/(ZnCdS:GO(1:1) doped PVP)/n-Si and Au/(ZnCdS:GO(1:0.5) doped PVP)/n-Si (MPS) type SDs which are named as SD1 and SD2, respectively, were fabricated onto the same n-Si wafer to determine effect of the rates of them using the I–V and C/G-V measurements. The basic electrical-parameters of them such as reverse-saturation current (I_s), ideality-factor (n), barrier-height (Φ_B), rectification-ratio (RR), series/shunt resistances (R_S, and R_sh) values, were calculated from the I–V data-based on thermionic-emission (TE) theory. The voltage dependence of surface -states profile was obtained from both the forward-bias I–V data (by considering voltage dependence of n, BH) and high–low frequency capacitance (C_LF–C_HF) methods for two SDs and were compared. These results indicate that SD2 has a lower leakage current and higher RR, R_sh, and BH than SD1 diode. On the other hand, the values of N_ss with the same order (∼10¹²–10¹³ eV⁻¹ cm²) for two SDs getting increases from the mid-gap of the semiconductor toward the bottom of the conduction band and change from region to region due to a particular density distribution of them in the bandgap. Both the voltage-dependent profile of N_ss and R_s was also extracted from the C/G-V data by using Nicollian–Brews and high–low frequency capacitance method, respectively, and the values of them for SD2 are lower than the SD1 in the whole measured voltage range.