A comparative electric and dielectric properties of Al/p-Si structures with undoped and Co-doped interfacial PVA layer

In this study, Al/p-Si structures with undoped and Co-doped PVA interfacial layer called S1 and S2 were fabricated and their both electrical and dielectric properties were compared by using 300 kHz capacitance-voltage (C-V) and conductance-voltage (G/ω−V) measurements at room temperature. Experimental results show that both C and G or dielectric constant (ε′), dielectric loss (ε″) values were found as strongly function of applied bias voltage especially at inverse and accumulation bias regions. It was found that the value of Rs considerably decreases with doping Co metal contrary to conductivity especially in the forward bias region. Such behavior can be attributed to the lack of free charges in pure PVA. The imaginary part of dielectric modulus (M″) gives two peaks for S1 corresponding to enough reverse and forward biases and passes from a minimum at about zero bias. Also, it is clear that the minimum of the M″ for S2 coincides with the maximum of the M″ for S1 at zero bias. As a result, Co-doped PVA considerable improved the performance of structure. In addition, loss tangent (tanδ), ac conductivity (σac) and real part of the electric modulus (M′) were obtained and compared each other.