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

Abstract

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