Low voltage copper phthalocyanine organic thin film transistors with a polymer layer as the gate insulator

Low voltage organic thin film transistors (OTFTs) were created using polymethyl-methacrylate-co g-lyciclyl-methacrylate (PMMA-GMA) as the gate dielectric. The OTFTs performed acceptably at supply voltages of about 10 V. From a densely packed copolymer brush, a leakage current as low as 2 x 10-8 A/cm2 was obtained. From the measured capacitance-insulator frequency characteristics, a dielectric constant in the range 3.9-5.0 was obtained. By controlling the thickness of the gate dielectric, the threshold voltage was reduced from -3.5 to -2.0 V. The copper phthalocyanine (CuPc) based organic thin film transistor could be operated at low voltage and 1.2 x 10-3 cm2/(V·s) mobility. (semiconductor devices)