Schottky diodes fabricated with Langmuir—Blodgett films of C60-doped poly(3-alkylthiophene)s

By dispersing poly(3-alkylthiophene)s (P3ATs) with surface-active materials such as arachidic acid (AA), three P3AT—AA—C60 mixed systems were fabricated into Y-type Langmuir—Blodgett (LB) films through the vertical dipping method with a transfer ratio close to unity. The LB films possess a well-layered structure, which was proved by small-angle X-ray diffraction patterns. The LB films were used to prepare model Schottky diodes and the current density—voltage characteristics of the diodes were measured. It was found that P3ATs became semiconductors after doping with C60 and the model diodes exhibited a rectification effect. The electronic parameters were found to be strongly dependent on the alkyl side chain length of P3AT molecules.