Low-voltage operated solid-state electrolyte-gated ambipolar organic field-effect transistors

Abstract

Abstract In this paper, we study the effect of the molecular structure of conjugated polymers on electron and hole transport in organic solid-state electrolyte-gated transistors (SEGTs) using three N,N′-difunctionalized naphthalene diimide (NDI)-based conjugated polymers with (5-methylselenophen-2-yl)vinyl)selenophen-2-yl [P(NDI-SVS)], 2,29-bithiophene [P(NDI2OD-T2)] and 3,3′-dichloro-2,2′-bithiophene [P(NDI2HD-T2Cl2)], respectively. The polymer transistors show electron mobility in the order of 10−2 ∼ 10−3 cm2 V−1 s−1 with very low operating voltage (2 V) using a solution processed solid-state electrolyte gate insulator which is composed of poly (vinylidene fluoride-trifluoroethylene) (99.5 vol%) and ion gel, based on poly (vinylidene fluoride-co-hexafluoropropylene) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ion liquid (0.5 vol%). Interestingly, P(NDI-SVS) SEGTs showed remarkable hole mobility of 0.14 ± 0.02 cm2 V−1 s−1 owing to the large hole accumulation compared to ∼0.03 cm2 V−1 s−1 using the poly (methyl methacrylate) (PMMA) gate dielectric. By controlling the molecular structure, we demonstrate high performance ambipolar SEGTs with P(NDI-SVS) polymer.