Studying electrical characteristics of Al₂O₃/PVP nano-hybrid composites as OFET gate dielectric

Al₂O₃/PVP nano-hybrid composite samples are synthesized using Sol–Gel method at 80 °C. Weight percent of poly 4-vinyl phenol (PVP) and aluminum oxide is 0.0, 0.28, 0.56, and 0.84. To study the nano-structural and electrical characteristics, X-ray diffraction, Fourier transfer infrared radiation, scanning electron microscopy, and atomic force microscopy are used. Dielectric constant of the samples is calculated using GPS 132A technique. The results show that the highest amounts of dielectric constant at the frequency of 120 and 1 kHz are related to Al₂O₃/0.28 wt% PVP (AP 0.28 wt%). PVP (k = 35) and Al₂O₃/0.56 wt% PVP (AP 0.56 wt%). PVP (k = 26) nano-composite samples, respectively. Therefore, at the frequency of 120 kHz, AP 0.28 wt% PVP nano-composite sample, due to having higher equivalent oxide thickness, less roughness, ohmic properties, smaller size of nano-crystallites (Scherrer diameter of 45 nm), higher dielectric constant, and as a result less leakage current, is recommended as the gate dielectric for the future of organic field effect transistors (OFET).