A comparative study on dielectric behaviours of Au/(Zn-doped PVA)/n-4H-SiC (MPS) structures with different interlayer thicknesses using impedance spectroscopy methods

Abstract

Three different thicknesses (50, 150 and 500 nm) Zn-doped polyvinyl alcohol (PVA) was deposited on n-4H-SiC wafer as interlayer by electrospinning method and so, Au/(Zn-doped PVA)/n-4H-SiC metal-polymer-semiconductor structures were fabricated. The thickness effect of Zn-doped PVA on the dielectric constant (ε), dielectric loss (ε), losstangent (tan δ), real and imaginary parts of electric modulus (M and M) and ac electrical conductivity (σ ac) of them were analysed and compared using experimental capacitance (C) and conductance (G/ω) data in the frequency range of 1-500 kHz at room temperature. According to these results, the values of ε and ε decrease with increasing frequency almost exponentially, σ ac increases especially, at high frequencies. The M and M values were obtained from the ε and ε data and the M and M vs. f plots were drawn for these structures. While the values of ε , ε and tan δ increase with increasing interlayer thickness, the values of M and M decrease with increasing interlayer thickness. The double logarithmic σ ac vs. f plots for each structure have two distinct linear regimes with different slopes, which correspond to low and high frequencies, respectively, and it is prominent that there exist two different conduction mechanisms. Obtained results were found as a strong function of frequency and interlayer thickness.

The interfacial properties of Au/n-4H-SiC structure with (Zn-doped PVA) interfacial layer

“…In the light of the obtained above experimental results and similar obtained results in the literature [21,22,37,38], the main scientific and technical challenge is to the increase the performance of the metal-semiconductor (MS) type Schottky diodes or solar cells (SCs) by using an alternative interfacial layer with high dielectric constant. The interfacial layer can be deposited by simple methods such as electrospinning and electrospinning methods at room temperature and its thickness can be controlled.…”

“…The measurements of C-V and G/ω-V of this structure were carried out in a wide frequency range of 1-400 kHz and a voltage range of (−1 V)-(6 V) at room temperature by using an HP4192A LF impedance analyzer. More detailed information about the cleaning procedure, the fabrication process, and the schematics diagrams of these structures can be found in our previous study [21,22].…”

“…Especially, in comparison with 3C-SiC and 6H-SiC, the 4H-SiC is the most widely used poly type of SiC because it has a wide band gap energy (E g ) and a highest mobility [17,19]. On the other hand, the use of high dielectric material or polymer interfacial layer between M and S causes electric properties advancements of contacts by providing lower values of N ss and R s at structure [21][22][23]. Recently, the polyvinyl alcohol (PVA) has become a highly used polymer as an interfacial layer at M/S interlayer due to its properties such as higher film formation capacity and tunable conductivity [9,24].…”

“…Recently, the polyvinyl alcohol (PVA) has become a highly used polymer as an interfacial layer at M/S interlayer due to its properties such as higher film formation capacity and tunable conductivity [9,24]. The doping of the polymers with the suitable metals is an important feature that enhances the conductivity of the polymer [21][22][23][24][25][26].…”

The effect of Cobalt-60 gamma irradiation on dielectric parameters and junction features of the Al/Orange G/p-Silicon diode

“…In addition, ε′ values are almost independent of frequency and voltage in the inversion section, while they decrease with increasing frequency in the depletion and accumulation sections. The reason why the ε′ and ε″ values are high at low frequencies can be attributed to the interface polarization mechanism, which occurs as a result of the effect of the gap charges in the sample on the image charges on the electrodes [82][83][84][85][86]. On the other hand, the peaks observed in the accumulation section at low frequencies (f100 kHz) result from the effect of series resistance and the OG interlayer.…”