The preparation of metal-polymer-semiconductor (MPS) and investigation of their electrical and dielectric properties based on frequency and temperature

In this thesis study, electrical and dielectric parameters of Al/p-Si Metal-Polymer-Semiconductor (MPS) type structures with CdS-PVA interfacial layer were investigated using the capacitance (C-V), conductance-voltage (G/ω) and current voltage (I-V) measurement data. CdS-PVA nanoparticles were produced using ball milling method and were coated on p-Si by sol-gel method. The process of production of Al/(CdS-PVA)/p-Si type structures were completed by forming omic and rectifier contacts via thermal evaporation method. Al/(CdS-PVA)/p-Si type structures' structural properties were examined with UV-VİS, X-Ray Powder Diffraction (XRD) and Scanning Electron Microscope (SEM). Dielectric properties such as complex dielectric (ε', ε''), loss tangent (tanδ), ac electrical conductivity (σac), complex electrical modulus (M', M'') were analyzed in temperature range of 230-340 K at 500 kHz, frequency range of 5 kHz-5 MHz, voltage range of ±1.0 V range. The values of ε', ε'', tanδ and of σac are almost stable at high frequencies and low temperatures whereas, at low frequencies and high temperatures, the values of ε', ε'', tanδ and σac show an increase because of interfacial polarizations and surface state (Nss) that follows ac signal easily. M' and M'' values increase with the increasing frequency and are observed to decrease with the increasing temperature. This situation was attributed to restructuring and reordering of the interfacial charges by the effect of dc voltage, frequency and temperature. For the purpose of determining relaxation mechanisms of Al/(CdS-PVA)/p-Si type structures the Argand diagram that was obtained from M' and M'' graphics was analyzed as a function of temperature. The voltage and frequency dependent profiles of density of Nss were investigated with high-low frequency capacitance (CLF-CHF) and Hill-Coleman methods whereas Rs values were obtained using Nicollian and Brews method. It was observed that Nss and Rs values decreased with the increasing frequency. Moreover, corrected capacitance (Cc) and corrected conductance (Gc/ω) graphics were drawn to eliminate the effect of Rs.