Investigation of electrical properties of Au/(NiS:PVP)/n-Si (MPS) structure using capacitance-voltage (C-V) and conductance-voltage (G/w-V) measurements depending on frequency

The NiS structure prepared for the interface of our diode structure, which is the research subject of the thesis, was obtained by the microwave-assisted method, and this method has recently attracted great attention in nano-scale syntheses. The polyvinylpyrrolidone (PVP) polymer structure also used for the interface is semi-crystalline and has a wide crystallinity range. Especially, thanks to its good solubility in both water and many organic solvents, it has found a place in many industrial areas due to its non-toxic characters and unique physical and chemical properties. In metal-semiconductor contacts, these organic polymers are widely used in order to eliminate the interface conditions that significantly affect the performance of the device by doping them with metal or metal compounds. The NiS nano-structures obtained in powder form were dissolved in deionized water as a solution to obtain a suitable PVP solution, and the NiS:PVP solution formed was mixed under room conditions and coated with a thin film layer on the semiconductor crystal surface by spin coating method. With ohmic contact coated on the crystal back surface, Schottky contacts on NiS:PVP structure were covered by the thermal evaporation method. Both capacitance-voltage (C-V) and conductivity-voltage (G/ω-V) characteristics of the prepared Au/(NiS:PVP)/n-Si diode structure, at room temperature, have a wide frequency and voltage. The measured electrophysical parameters showed strong frequency dependency characteristics in the depletion and accumulation region. These effects are due to the presence of the organic interfacial layer (NiS:PVP) as well as the interfacial states (Nss), series resistor (Rs), and polarization.