Investigation of Negative Capacitance in Admittance Analysis of Metal Semiconductors Interlayered With ZnFe2O4 Doped PVA

Abstract

In this work, Al/p-Si structures with (ZnFe ₂ O ₄ − PVA) interfacial film, which is grown by the electrospinning-method, have been analyzed by using impedance measurements in the wide frequency interval (2 kHz–2 MHz) at both side of polarization (±4 V). Some fundamental important electrical parameters such as intercept-voltage (V _o ), the concentration of acceptor-atoms (N _A ), depletion layer width (W _d ), and barrier-height (Φ _B ) were extracted from intercept and slope of the 1/C ² vs V plot in the inversion region for each frequency. It has been observed that parameters such as the presence of surface states (N _SS ), relaxation or lifetimes (τ), organic interlayer, dipoles or surface polarization in the inversion and depletion regions, especially at low and moderate frequencies, are obviously dependent on the frequency and applied biases. The voltage and frequency dependence profile of the series resistor (R _S ), N _SS, and also τ were determined from the Nicollian-Brews method and Nicollian-Goetzberger conductance technique, respectively. The magnitude of N _SS and the values of τ were calculated from the maximum value of (G _P /ω) related to the frequency for different voltage values. The negative capacitance (NC) at about zero biases and the source of the two incongruous peaks in the depletion and accumulation zones were also discussed. While the first peak in the depletion region was a result of N _SS , the second peak in the depletion region was caused by the effect of R _S .