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

Abstract

High‐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.

Ultraviolet Light-Activated Charge Modulation Heterojunction for Versatile Organic Thin Film Transistors

“…The excitons of PTCDI at the P3HT/PTCDI heterojunction can be dissociated by their HOMO difference, causing hole transfer from PTCDI to P3HT. The hole mobility of P3HT and the electron mobility of PTCDI can reach above 10 –1 cm 2 V –1 s –1 and are comparable. − ,− Resultantly, the electrons from exciton dissociation are not as localized in PTCDI as in Alq3, and the holes from exciton dissociation can contribute to the hole current of the P3HT layer. Therefore, in the time-resolved I D measurement, an increased I D value of the PTCDI/Alq3-covered device during the green light irradiation is observed (Figure f).…”

Multicomponent Blend Systems Used in Organic Field-Effect Transistors: Charge Transport Properties, Large-Area Preparation, and Functional Devices

“…The subthreshold slope (−0.20 V dec –1 ) and on/off current ratio (10 6 ) were also ideal from a practical viewpoint. Then they expanded the scope of this system and studied SEGIs based on the high-κ terpolymer P­(VDF-TrFE-CTFE) . The introduction of P­(VDF-HFP)-[EMIM]­[TFSI] bound the grain boundaries of the terpolymer, and the formation of the EDLs increased the capacitance from 49.12 nF cm –2 to 5.5 μF cm –2 .…”

“…Then they expanded the scope of this system and studied SEGIs based on the high-κ terpolymer P(VDF-TrFE-CTFE). 55 The introduction of P(VDF-HFP)-[EMIM][TFSI] bound the grain boundaries of the terpolymer, and the formation of the EDLs increased the capacitance from 49.12 nF cm −2 to 5.5 μF cm −2 . These works are of great significance for using SEGIs to prepare high-performance organic transistors.…”

Ultraviolet Light-Densified Oxide-Organic Self-Assembled Dielectrics: Processing Thin-Film Transistors at Room Temperature

“…Silicon dioxide (SiO 2 ) is a widely utilized gate dielectric not only in silicon-based complementary metal oxide semiconductor field-effect transistors (CMOS-FETs) but also for thin-film transistors (TFTs) based on metal oxide, nanowire/nanorod, two-dimensional, and organic semiconductors. − To accelerate advances in electronic circuit performance, high- k metal oxide gate dielectrics, such as ZrO x and HfO x , have attracted great research interest owing to their large dielectric constants (∼25), high dielectric strength (6–30 MV/cm), low loss (<0.2), and low interfacial/bulk trap densities. − Although the best performing metal oxide dielectric films are currently fabricated using vapor phase processes such as chemical vapor deposition, atomic layer deposition, and magnetron sputtering, increasing efforts have been devoted to realizing solution-based, room temperature processes for reducing electronic device costs and enabling their fabrication by roll-to-roll/printing on flexible substrates such as plastics. − Indeed, high- k metal oxide dielectric films have been successfully implemented in low-voltage/power TFTs for organic CMOS. − …”