| 초록 |
For the organic field-effect transistor with electrically stable operation, we synthesize fluorinated polyimide polymers as gate dielectrics: F6-PI and F18-PI. F6-PI and F18-PI polymers contain 6 and 18 fluorine atoms per repeat unit. In particular these fluorinated polymers show smooth surface topography, and lower surface energy values with increasing fluorine atom in polymer backbone, which leading to better crystalline morphology of the semiconductor film grown on them. With these fluorinated polyimide dielectrics, we demonstrated low-operating OFETs with pentacene and triethylsilylethynyl anthradithiophene. The number of fluorine atoms in polyimide backbone was increased, the field-effect mobility was improved, and threshold voltage was positively shifted (from -0.41 V to +2.21 V). In particular, highly fluorinated polyimide could realize electrical stability behaviors at both ambient air and N2 environment: negligible hysteresis and small shift of Vth under gate-biasing. |
