@article{article_369147, title={Effects of Frequency and Bias Voltage on Dielectric Properties and Electric Modulus of Au/Bi4Ti3O12/n-Si (MFS) Capacitors}, journal={Politeknik Dergisi}, volume={20}, pages={1003–1008}, year={2017}, DOI={10.2339/politeknik.369147}, url={https://izlik.org/JA49SH25HU}, author={Durmuş, Perihan and Bilkan, Çiğdem and Yıldırım, Mert}, keywords={MFS capacitors,frequency and voltage dependence,surface states and interfacial polarization,dielectric properties and electrical modulus}, abstract={<p class="MsoNormal" style="margin-top:3.0pt;margin-right:0cm;margin-bottom:3.0pt; margin-left:0cm;text-align:justify"> <span lang="EN-US" style="font-size:9.0pt; mso-bidi-font-size:10.0pt;font-family:"Times New Roman",serif;mso-ansi-language: EN-US">In this work, a metal-ferroelectric-semiconductor (MFS) type capacitor was fabricated and admittance measurements were held in a wide frequency range of 1 kHz-5 MHz at room temperature for the investigation of frequency and voltage dependence of complex dielectric constant, complex electric modulus and electrical conductivity <span style="background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">of </span>the MFS capacitor <span style="background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">. </span>Bismuth titanate (Bi <sub>4 </sub>Ti <sub>3 </sub>O <sub>12 </sub> <span style="background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">) </span> with high dielectric constant was used as interfacial ferroelectric material and the structure of MFS capacitor was obtained as Au/Bi <sub>4 </sub>Ti <sub>3 </sub>O <sub>12 </sub>/n-Si. Experimental results showed that dielectric, modulus and conductivity parameters are strong functions of frequency and voltage especially in depletion and accumulation regions due to the existence of surface states (N <sub>ss </sub>), series resistance (R <sub>s </sub>), interfacial polarization and interfacial layer. It was found that R <sub>s </sub> of the structure and interfacial ferroelectric layer are efective in accumulation region whereas surface states (N <sub>ss </sub>) and interfacial polarization are efective in depletion region. Also the changes in dielectric, modulus and conductivity parameters become considerably high particularly at low frequencies due to high values of R <sub>s </sub> and N <sub>ss </sub>. The observed anomalous peak in voltage dependent plots of capacitance and dielectric constant was atributed to the particular density distribution of N <sub>ss </sub>, R <sub>s </sub> and minority carrier injection. Moreover, the value of <span style="border: 1pt none windowtext; padding: 0cm; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">conductivity </span> at low and intermediate frequencies is almost independent of frequency thus low frequency data was used to extract d.c. conductivity. This work showed that the use of high-dielectric Bi <sub>4 </sub>Ti <sub>3 </sub>O <sub>12 </sub> as ferroelectric interfacial layer in a MFS capacitor is preferable due to high values of its dielectric constant compared with traditional insulator layer materials such as SiO <sub>2 </sub> and SnO <sub>2 </sub>. Therefore, a MFS capacitor with Bi <sub>4 </sub>Ti <sub>3 </sub>O <sub>12 </sub> interfacial layer can store more energy thanks to its high dielectric constant. <o:p> </o:p> </span> </p>}, number={4}