A comparative study of the Au/n-Si (MS) and Au/(ZnO:CeO2:PVP)/n-Si (MPS) Schottky structures by using current/voltage characteristics in dark and under illumination

In the present study, both metal/semiconductor (MS) and metal/polymer/semiconductor (MPS) Schottky Diodes (SDs) were grown onto the same n-Si wafer to compare their electrical and optical characteristics. Firstly, ZnO and CeO2 nanostructures were synthesized by ultrasonic-assisted method (UAM), and structurally characterized by utilizing x-ray diffraction (XRD), Ultraviolet-visible spectroscopy (UV-vis), and Fourier-Transform-IR (FTIR) methods. The mean submicron crystallite sizes were estimated to be below 11.39 nm for CeO2 and 54.37 nm for ZnO nanostructures through the Debye-Scherrer method. The optical bandgap was calculated as 3.84 eV for CeO2 and 3.88 eV for ZnO nanostructures via Tauc plot. Electrical parameters such as reverse-saturation current (Io), ideality-factor (n), zero-bias barrier height (Phi(Bo)), and rectification-ratio (RR) were found as 0.596 mu A, 5.45, 0.64 eV, 2.74 x 10(5) in dark and 5.54 mu A, 5.88, 0.59 eV, 8.60 x 10(3) under illumination for the MS SD and 0.027 mu A, 4.36, 0.72 eV, 1.85 x 10(7) in dark and 0.714 mu A, 5.18, 0.64 eV, 7.61 x 10(4) under illumination for the MPS SD, respectively. The energy-dependent profile of surface-states was obtained via the Card-Rhoderick method, by considering Phi(B)(V) and n. RR of the MPS SD is almost sixty-seven times the RR of the MS SD in the dark. The sensitivity of the MPS SD (=710) is nineteen and five-tenths the sensitivity of the MS SD (=36.4), so the MPS SD is considerably more sensitive to illumination. These results indicate that the (ZnO:CeO2:PVP) organic interlayer significantly improves the performance of the MS SD.