Frequency and voltage dependence of electrical conductivity, complex electric modulus, and dielectric properties of Al/Alq₃ /p-Si structure

Authors: İKRAM ORAK, ABDULKERİM KARABULUT

Abstract: In order to enhance the capacitance of the Al/p-Si metal-semiconductor structure, the Alq₃ thin film was coated between these two layers using the spin coating technique as the interlayer. The electrical conductivity, real and imaginary parts of electric modulus, dielectric loss and dielectric constant parameters were examined at the room temperature by the help of admittance measurements in the 100 kHz to 1 MHz frequency range. The effect of frequency on the dielectric constant and dielectric loss values is negligible at the negative voltage values, up to about 0.8 V, and these values rapidly ascended after 0.8 V. The function of electrical modulus complex has been examined from the point of permittivity and impedance in order to clutch the contribution of the particle border on the relaxation mechanism of the materials. It is established that the examined dielectric parameters strongly correlated with the voltage and frequency. As a result, the changes in the dielectric parameters and electrical modulus due to the varying frequency were described as the results of relaxation process, polarization and surface conditions. Furthermore, it could be stated that the Alq₃ material used in the interfacial layer is a useful material which could be used in addition to the conventional materials.

Keywords: Dielectric properties, spin coating, Al/Alq₃ /p-Si, frequency and voltage dependency

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