Illumination Dependent Admittance Characteristics of Au∕Zinc Acetate Doped Polyvinyl Alcohol (PVA:Zn)∕n-Si Schottky Barrier Diodes (SBDs)

Abstract

This study presents the effect of illumination on main electrical parameters of Schottky barrier diode (SBD). The admittance (capacitance‐voltage (C‐V) and conductance‐voltage (G/ω‐V)) characteristics of Au/Zinc acetate doped polyvinyl alcohol (PVA:Zn)/n‐Si SBD were investigated in dark and under various illumination intensities. Experimental results demonstrate that the C‐V plots give a peak due to the illumination induced interface states or electron‐hole pairs at metal/semiconductor (M/S) interface. The C−2‐V plots were also drawn to determine main electrical parameters such as doping concentration (ND), depletion layer width (WD) and barrier height (ΦB(C‐V)) of device. In addition, the voltage dependence Rs values were obtained from C‐V and G/ω‐V data by using Nicollian and Brews method. In order to obtain the real diode capacitance and conductance, the high frequency (1 MHz) Cm and Gm/w values were corrected for the effect of series resistance. All these observations confirm that both C‐V and G/w‐V characteristics were strongly affected by illumination.