The Effect Of Temperture And Frequency On Electrıcal Parameters Of Au/(Cu2o-Cuo-Pva)/N-Si Metal-Polymer-Semıconductor Structure


Thesis Type: Doctorate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2018

Student: AYSEL BÜYÜKBAŞ ULUŞAN

Supervisor: ADEM TATAROĞLU

Abstract:

In this study, the Cu2O-CuO-PVA composite material was deposited on n-Si substrate by using spin coating method. The composite material was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effect of temperature and frequency on electrical parameters of the prepared Au/(Cu2O-CuO-PVA)/n-Si metal-polymer-semiconductor (MPS) structure has been investigated by using current measurements performed in the temperature range of 100-380 K and admittance (Y=G+iωC) measurements performed in the frequency range of 10 kHz-3 MHz. The measured forward bias current-voltage (I-V) characteristics were analyzed on the basis of thermionic emission (TE) theory. While the zero-bias barrier height (Φb0) value determined from I-V measurements increases with increasing temperature, the ideality factor (n) decreases. This behavior of n and Φb0 was attributed to the inhomogeneous barrier heights by assuming a Gaussian distribution (GD) at the M/S interface. It is found that the barrier height values obtained from the I-V and Norde method are in good agreement with each other. Frequency dependence of capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics is attributed to the presence of interface states at S/P interface. The electrical parameters such as interface state density (Nss) and series resistance (Rs) values of the MPS structure were calculated from both I-V and C/G-V measurements. Moreover, the equivalent circuit model parameters such as parallel resistor (Rp), parallel capacitor (Cp) and series resistance were detemined impedance measurements carried out in the frequency range of 100 Hz-1 MHz. The experimental results show that the obtained electrical parameters are strongly dependent on temperature, frequency and applied voltage. Consequently, the prepared MPS structure can be used as a Schottky diode in various electrical and electronic circuits.