Preparation of Al/(BSA doped PANI)/p-InP schottky diode and investigation of frequency dependent dielectric properties

In this thesis, Benzen Sülfonic acid doped Polyaniline (PANI-BSA) interface layered Schottky Diode (SD) was prepared and both the electrical and dielectric properties of this diode was investigated in a wide frequency and voltage range. Firstly, PANI-BSA and pure PANI polymers were synthesized. Structural properties of the obtained PANI-BSA and PANI samples were determined by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet Visible spectroscopy (UV-Vis). Band gap of PANI-BSA and PANI polymers were calculated as 2,32 and 2,88 eV, respectively, with the help of Kubelka-Munk equation. PANI-BSA showed high resolution in DMSO. Secondly, it was coated as thin film as an interface on the synthesized PANI-BSA InP and, Al/(BSA doped-PANI)/p-InP SD structure was prepared. The interface, which has the potential to affect the diode feature, has also been used to regulate the charge transfer between metal and semiconductors. Using the data of capacitance and conductivity voltage (C&G/ω-V) measured in the range of 1-200 kHz of SD, the complex transmittance (ε*=ε'-jε''), the lost tangent (tanδ), the complex electrical module (M*=M'+ jM'') and electrical conductivity (σ) has been investigated in detail depending on frequency and voltage. Due to polarization and surface conditions (Nss), large differences were observed in all these parameters, especially at low frequencies. Such behaviors depending on frequency and voltage in ε', ε'' and tanδ are explained by the relaxation of Maxwell-Wagner-Sillars. While conductivity (σ) values are almost unchanged at low-medium frequencies, DC and AC conductivity values started to increase at high frequencies. The values of M 'and M' in the low frequency region are low and the short distance charge carriers increase with increasing frequency due to their mobility. Ultimately, these frequency-dependent changes have been attributed to the presence of interface states, their lifetimes, polarization, and reorganization and regulation under voltage.