[Abstract]

We report a cross-linkable diblock copolymer at a mild temperature by Diels-Alder click-chemistry for a gate dielectric layer in the top-gate, bottom contact organic field-effect transistors (OFETs). The Diels-Alder reaction between poly[(methyl methacrylate)-co-(9-anthracenyl methyl methacrylate)] (P(MMA-AMA)) and 1,1′-(methylenedi-4,1-phenylene)bismaleimide (MPB) enables the preparation of robust cross-linked films at 100 °C annealing for 10 min. Poly(9,9-dioctylfluorene-alt-bithiophene (F8T2) or poly(3-hexylthiophene) (P3HT) OFETs exhibited charge carrier mobilities of 3 ∼ 4 × 10−3 cm2 V−1 s−1 with the 250 nm thick crosslinked (P(MMA-AMA)) films at gate voltages of less than −20 V. Moreover, the ratio of MMA and AMA was controlled to observe the effects of crosslinking density on the properties of the gate dielectric layer. When the portion of a crosslinkable anthracenyl unit in (P(MMA-AMA)) is increased to 50 mol.% in the base polymer, the gate leakage current of OFETs decreases below 10−8 A at Vg = −20 V.