Solid‐State Electrolyte Dielectrics Based on Exceptional High‐k P(VDF‐TrFE‐CTFE) Terpolymer for High‐Performance Field‐Effect Transistors

Abstract

AbstractHigh‐performance and low‐voltage organic and inorganic field‐effect transistors (FETs) with solid‐state electrolyte gate insulator that is composed of an exceptional high‐k fluorinated dielectric and an ion‐gel‐blend polymer matrix are reported. The structuring polymer is high‐k poly(vinylidenefluoride‐trifluoroethylene‐chlorotrifluoroethylene) (P(VDF‐TrFE‐CTFE)) terpolymer. The ion gel is made of poly(vinylidene fluoride‐co‐hexafluroropropylene) (P(VDF‐HFP)) and 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI]) ion liquid. The blend polymer matrix has high measured capacitance of ≈2 to 5.5 µF cm−2 at 100 Hz, which is attributed to formation of electrical double layers (EDLs) at the insulator/semiconductor interface. High effective carrier mobility (μeff) and low operating voltage ≤2 V with just 0.5 v% of P(VDF‐HFP)‐[EMIM][TFSI] solution in the bulk P(VDF‐TrFE‐CTFE) insulating layer are demonstrated, coupled with low gate‐leakage current levels. Excellent μeff = 1.30 ± 0.19 cm2 V−1 s−1 is achieved in P3HT FETs with SEGI, which is a remarkable boost from 0.48 ± 0.09 cm2 V−1 s−1 at 30 V when pure P(VDF‐TrFE‐CTFE) dielectric is used. Other semiconductors are also tested: IGZO has μeff = 11.09 ± 2.07 cm2 V−1 s−1, and PDFDT has μeff = 2.42 ± 0.46 cm2 V−1 s−1. These remarkable increases in mobility are attributed to the high concentration of induced carriers in the semiconducting channel.