illumination intensity and applied bias voltage on dielectric properties of au/polyvinyl alcohol (Co, Zn-doped)/n-Si Schottky barrier diodes

The Au/polyvinyl alcohol (PVA) (Co, Zn-doped)/n-Si Schottky barrier diodes (SBDs) were exposed to various illumination intensities. Illumination effect on the dielectric properties has been investigated by using capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics at 1 MHz and room temperature. The values of dielectric constant (ε′), dielectric loss (ε″), loss tangent (tanδ), electric modulus (M′ and M″), and AC electrical conductivity (σAC) were found strongly intensity dependent on both the illumination levels and applied bias voltage especially in depletion and accumulation regions. Such bias and illumination dependency of these parameters can be explained on the basis of Maxwell-Wagner interfacial polarization and restructuring and reordering of charges at interface states. In addition, the ε′-V plots also show an intersection feature at ∼ 2.8 V and such behavior of the ε′-V plots appears as an abnormality compared with the conventional behavior of an ideal SBD. The obtained results revealed that illumination intensity enhances the conductivity of Au/PVA(Co, Zn-doped)/n-Si SBD.