Investigation of photovoltaic effect on electric and dielectric properties of Au/n-Si Schottky barrier diodes with nickel (Ni)-zinc (Zn) doped organic interface layer

Photovoltaic effects were tracked on both electric and dielectric properties of Au/(Ni, Zn)-doped polyvinyl alcohol/n-Si Schottky barrier diodes as function of illumination intensity by 50 W steps at 1 MHz and in the voltage interval of (- 4)-(+ 5) V. The measurements indicate that ac electrical conductivity (sigma (ac) ), dielectric constant's both real and imaginary parts (epsilon', epsilon aEuro(3)), loss tangent (tan delta) and electric modulus (M', MaEuro(3)) are highly relevant functions of illumination and voltage. The variations in depletion region can be ascribed to the charges at interface and its reordering and restructuring under illumination and electric field but then accumulation region variations can be ascribed to the interfacial layer and series resistance (R (s) ). The values of epsilon(EE1)-E-1 and tan delta show a step increase with the increasing voltage for each illumination intensity while the values of epsilon' show an anomalous peak (similar to 1.4 V). C-V plot shows an intersection behavior at about 2.2 V due to lack of enough free charges in low illumination. The values of sigma (ac) increase with increasing illumination and voltage due to the formation electron-hole pairs. The MaEuro(3) vs V have two peaks for each illumination intensity and peak value increases with increasing illumination intensity and its positions tend to shift towards low voltage region.