Organic thin-film transistors on plastic substrates

In this paper, organic thin-film transistors (OTFTs) were fabricated on polyethersulfone (PES) and silicon (Si) substrates with top-contact geometry. Several kinds of metals with different work functions were used for source and drain electrodes, and optimum fabrication conditions were found. Photo cross-linkable polymeric gate dielectrics and thermal silicone oxide (SiO2) were used for the plastic and Si OTFTs, respectively. From the electrical measurements, typical I-V characteristics of the thin-film transistor (TFT) were observed. The field-effect mobility, μ, was obtained to be 2.59 cm2/(V s) from the flexible OTFT with polymeric gate dielectrics. Moreover, a possible critical work function of 4.3 eV for the electrode of pentacene OTFT with top-contact geometry.