Dielectric properties, electrical modulus and current transport mechanisms of Au/ZnO/n-Si structures

Badali Y., ALTINDAL Ş. , USLU İ.

PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL, vol.28, no.3, pp.325-331, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 3
  • Publication Date: 2018
  • Doi Number: 10.1016/j.pnsc.2018.05.003
  • Page Numbers: pp.325-331


Au/ZnO/n-Si (MIS) structures were fabricated by using the RF sputtering method and their complex dielectric constant (epsilon*= epsilon'-j epsilon"), electric modulus (M*=M' + jM") and electrical conductivity (sigma = sigma(dc) + sigma(ac)) values were investigated as a function of frequency (0.7 kHz-1 MHz) and voltage (- 6 - ( + 6 V)) by capacitance-voltage (C-V) and conductance-voltage (G/omega-V) measurements to get more information on the conduction mechanisms and formation of barrier height between Au and n-Si. The In sigma-Inf plots have two different regions corresponding to low-intermediate and high frequencies. Such behavior of In sigma-Inf plots shows that the existence of two different conduction mechanisms (CMs) at low-intermediate and high frequencies. Moreover, the reverse bias saturation current (I-0), ideally factor (n), barrier height (Phi(B0)) were determined from the forward bias I-V data and they were found as a strong function of temperature. The value of n especially at low temperature is considerably higher than unity. The values of (Phi) over bar (B0) and standard deviation(sigma(s)) were found from the intercept and slope of (Phi) over bar (B0)-q/2kT plots as 0.551 eV and 0.075 V for the region I (80-220 K) and 1.126 eV and 0.053 V for the region II (220-400 K), respectively. The values of (Phi) over bar (B0) and effective Richardson constant (A*) were found from slope and intercept of activation energy plots as 0.564 eV and 101.084 Acm(-2) K-2 for the region I and 1.136 eV and 41.87 Acm(-2) K-2 for the region II, respectively. These results confirm that the current-voltage-temperature (I-VT) characteristics of the fabricated Au/ZnO/n-Si SBDs can satisfactorily be explained on the basis of TE theory with double GD of the BHs.