Origin of frequency and voltage dependent negative dielectric properties in the Al/p-Si Schottky diodes with (Cd0.3Zn0.7O) interfacial layer in the wide range of frequency and voltage

Abstract

The real and imaginary parts of complex-dielectric (ε′, ε'') and electric-modulus (M′, M″), dielectric loss tangent (tanδ), and conductivity (σ) values of Al/(Cd0.3Zn0.7O)/p-Si Schottky Diode (SD) were obtained from capacitance/conductance vs. voltage/frequency (C/G-V-f) plots. Negative dielectric (ND) was observed under 50 kHz at about 3.5 V and the increase in the ε'' results from a drop in ND with increasing voltage, also known as inductive behavior. The rise in σac at high frequencies causes the eddy-current to grow, which in turn causes the ε” or tanδ to increase. While the relaxation process causes the value of M′ to decrease with increasing voltage, M″-V graphs reveal a peak at roughly 0.0V for each frequency. The obtained value of ε′ for Al/(Cd0.3Zn0.7O)/p-Si at 500 Hz is about 25 times higher than those using traditional SiO2 as an interfacial layer, and so it can be successfully used for more charge or energy storage.