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

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) similar to 10(-3) cm(2) 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 cm(2) V-1 s(-1) owing to the large hole accumulation compared to similar to 0.03 cm(2) 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.