The analysis of f4-tcnq concertration dependentc-v and G/w-V characteristics of AU/P3HT:F4-TCNQ/N-Sİ Schottky barrier diodes

ABSTRACT THE ANALYSIS OF F4-TCNQ CONCENTRATION DEPENDENT C-V AND G/w-V CHARACTERISTICS OF AU/P3HT:F4-TCNQ/N-SI SCHOTTKY BARRIER DIODES Aslıhan DANACI Düzce University Graduate School of Natural and Applied Sciences, Department of Composite Material Technologies Master's Thesis Supervisor: Assoc. Prof. Dr. Özge TÜZÜN ÖZMEN 21/11/2019, 40 pages In recent years, devices produced using organic materials in optoelectronic technology have become one of the attractive areas. Organic semiconductors used in organic electronic devices are highly preferred because they are mechanically flexible, they can be grown on the surface with simple techniques and they have wide variety of syntheses. Devices obtained using organic semiconducting materials can be classified as organic light emitting diodes (OLED), organic thin film transistors (OTFT) and Schottky barrier diodes (SBD) according to their functions. Schottky barrier diodes, which are often used because of their importance in electronic and optoelectronic applications, are materials that are constantly needed in the technological space due to their advantages such as they can easily conduct even at lower voltage values than other diodes in the right supply, and they have low noise levels and high yields. The choice of polymer at the polymer interface used in the production of metal-polymer-semiconducting (MPS) SBDs is very important, and these polymers must be highly conductive, mechanically stable and stable in the air environment. In this study, the electrical properties of Au/P3HT:F4-TCNQ/n-Si metal-polymer-semiconductor (MPS) Schottky barrier diodes (SBDs) with 0.5% and 2% F4-TCNQ concentrations were investigated using capatitance-voltage (C-V) and conductance-voltage (G/w-V) measurements. The C-V and G/w-V measurements of Au/P3HT:F4-TCNQ/n-Si MPS SBDs were performed in the large frequency range (10 kHz – 2 MHz) and in the voltage range from -10.0 V to +10.0 V. By using C-V and G/w-V measurements as a function of F4-TCNQ concentration, series resistance (Rs) and interface states (Nss) were calculated. 2% F4-TCNQ concentration used diode yielded better electrical results, such as lower capacitance, lower series resistance, higher shunt resistance and lower Nss. Because of this, detailed C-V and G/w-V analysis were performed only for 2% F4-TCNQ concentration used diode. Diffusion potential (VD), doping concentration of donors (ND), depletion layer width (WD), barrier height (ΦB), Fermi energy level (EF), maximum electric field (Em) and Schottky barrier lowering (ΔΦB) values were obtained for 2% F4-TCNQ concentration used Au/P3HT:F4-TCNQ/n-Si SBD with C and G/w measurements. As a result, when frequency increased, the series resistance and density of interface states decreased. Finally, it can be concluded that the concentration of F4-TCNQ has a great effect on the electrical properties of the Au/P3HT:F4-TCNQ/n-Si SBDs. Additionally, the values of Rs and Nss directly affected the C-V and the G/w-V profiles of Au/P3HT:F4-TCNQ/n-Si SBDs. Keywords F4-TCNQ concentration, Frequency and voltage dependence, C-V and G/w-V analysis, Density of interface states, Series resistance