Electrical and dielectric properties and intersection behavior of G/ω-V plots for Al/Co-PVA/p-Si (MPS) structures at temperatures below room temperature

Abstract

Both the electrical and the dielectric properties of the Al/Co-doped polyvinyl alcohol/p-Si metal-polymer-semiconductor (MPS) structure have been studied using temperature-dependent admittance-voltage (C/G-V) measurements at temperatures below room temperature at 300 kHz. The C-V plot indicates two peaks for each temperature corresponding to inversion and accumulation regions, respectively. The first peak was attributed to a particular distribution of interface traps (D _it ), and the second was attributed to the series resistance (R _s ) and interfacial polymer layer. G/ω-V plots show almost U-shape behavior for all temperatures and a crossing at almost 3 V. Such behavior of the G/ω-V plots may be attributed to the lack of free charge at low temperatures. After this intersection point, while the value of the capacitance (C) starts decreasing, the G/ω continues to increase. The temperature-dependent real and imaginary parts of the dielectric constant (ε′, ε″) and of the electric modulus (M′, M″), as well as the ac electrical conductivity (σ _ac ), of structure were obtained using C and G data before and after the intersection point (at 2 and 6 V), respectively. Experimental results show that the ε′, ε″, loss tangent (tan δ), σ _ac , M′, and M″ values were strong functions of the temperature and the applied bias voltage. In addition, G/ω-T and ε″-T plots show two different behaviors, one before and the other after the intersection point.