Fabrication and Characterization of Copper Phthalocyanine- Based Field Effect Transistors

Abstract

Future generations of electronic products will be enabled by flexible electronic circuits, displays, and sensors based on organic active materials, which could eventually reach the mainstream electronics industry. One of such devices is the organic field-effect transistor (OFET), which are three-terminal devices that are comprised of a gate, source, and drain electrode. In this study, we fabricated a bottom-gate bottom-contact OFET device using copper phthalocyanine (CuPc) as a semiconducting layer. CuPc is a commercially available metal complex, a known p-type semiconducting material. Au/Ti electrode is sputtered on Al gated silicon substrate with thermally grown SiO2 dielectric layer. CuPc films were then deposited over the substrate with patterned electrodes by physical vapor deposition at a rate of 0.35 nm/s, recorded by a quartz crystal microbalance at room temperature under a background pressure of 1.21x10 Pa. A thin layer of organic material was also deposited on glass slides and the optical properties of films with different thicknesses were determined by UV-Vis spectrometry and the optical band-gap energy was determined to be 1.64±0.01 eV. The thermal annealing effect on thin-film crystallization morphology was studied with atomic force microscopy (AFM) and contact angle measurement.