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Temperature and frequency dependent dielectric properties of Au/Bi4Ti3O12/SiO2/Si (MFIS) structures

Ş. ALTINDAL1, F. PARLAKTÜRK1, A. TATAROĞLU1,* , M.M. BÜLBÜL1

Affiliation

  1. Physics Department, Faculty of Arts and Sciences, Gazi University, 06500, Ankara, Turkey

Abstract

The frequency and temperature dependence of dielectric constant (ε'), dielectric loss (ε''), dielectric loss tangent (tanδ) and the ac electrical conductivity (σac) of Au/Bi4Ti3O12/SiO2/Si (MFIS) structures were studied in the frequency range of 1 kHz–5 MHz and in the temperature range of 80-400 K. The dielectric parameters of MFIS structure were calculated from C-V and G/ω-V measurements. It was found that both dielectric and conductivity were quite sensitive to temperature and frequency at relatively high temperatures and at low frequencies. Experimental results show that the ε' and ε'' decrease with increasing frequency, while they increase with increasing temperature. On the other hand, the ac electrical conductivity (σac) increases with increasing frequency and temperature alike. The interfacial polarization can be more easily occurred at low frequencies, and the number of interface states density between semiconductor/insulator interfaces, consequently, contributes to the improvement of dielectric properties of MFIS structure. The values of activation energy (Ea) were obtained from the slope of the Ln vs q/kT plots, and found as 122.3 meV and 109.3 meV for 100 kHz and 500 kHz, respectively. In addition, the real (M') and imaginary (M'') components of the electrical modulus were calculated from the values of ε' and ε'' for two different frequencies. It was found that the values of real component M' decreases with increasing temperature up to room temperature, and then becomes independent of temperature and frequency..

Keywords

Au-/n-Si(111) SBDs, I-V-T and C-V-T caharacteristics, Interface states, Series resistance, Norde function.

Submitted at: Sept. 8, 2010
Accepted at: Oct. 14, 2010

Citation

Ş. ALTINDAL, F. PARLAKTÜRK, A. TATAROĞLU, M.M. BÜLBÜL, Temperature and frequency dependent dielectric properties of Au/Bi4Ti3O12/SiO2/Si (MFIS) structures, Journal of Optoelectronics and Advanced Materials Vol. 12, Iss. 10, pp. 2139-2143 (2010)