Difluorobenzothiadiazole and Selenophene-Based Conjugated Polymer Demonstrating an Effective Hole Mobility Exceeding 5 cm² V^–1 s^–1 with Solid-State Electrolyte Dielectric

Abstract

We report synthesis of a new poly(4-(4,4-bis(2-ethylhexyl)-4 H-silolo[3,2- b:4,5- b']dithiophene-2-yl)-7-(4,4-bis(2-ethylhexyl)-6-(selenophene-2-yl)-4 H-silolo[3,2- b:4,5- b']dithiophene-2-yl)-5,6-difluorobenzo[ c][1,2,5]thiadiazole (PDFDSe) polymer based on planar 4,7-bis(4,4-bis(2-ethylhexyl)-4 H-silolo[3,2- b:4,5- b']dithiophen-2-yl)-5,6-difluorobenzo[ c][1,2,5]thiadiazole (DFD) moieties and selenophene linkages. The planar backboned PDFDSe polymer exhibits highest occupied molecular orbital and lowest unoccupied molecular orbital levels of -5.13 and -3.56 eV, respectively, and generates well-packed highly crystalline states in films with exclusive edge-on orientations. PDFDSe thin film was incorporated as a channel material in top-gate bottom-contact organic thin-film transistor with a solid-state electrolyte gate insulator (SEGI) composed of poly(vinylidene difluoride-trifluoroethylene)/poly(vinylidene fluoride- co-hexafluroropropylene)/1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, which exhibited a remarkably high hole mobility up to μ = 20.3 cm V s corresponding to effective hole mobility exceeding 5 cm V s and a very low threshold voltage of -1 V. These device characteristics are associated with the high carrier density in the semiconducting channel region, induced by the high capacitance of the SEGI layer. The excellent carrier mobility from the PDFDSe/SEGI device demonstrates a great potential of semiconducting polymer thin-film transistors as electronic components in future electronic applications.

Donor–Acceptor‐Conjugated Polymer for High‐Performance Organic Field‐Effect Transistors: A Progress Report

“…In addition, the dithienosilole unit, a derivative of CDT, was copolymerized with fluorinated BT units to achieve P8 and P9 . Both polymers exhibited a relatively short π–π‐stacking distance (≈3.65 Å), because the Si–C bond, which is longer than the C–C bond, allows efficient intermolecular interactions .…”

Random copolymerization of polythiophene for simultaneous enhancement of in‐plane and out‐of‐plane charge transport for organic transistors and perovskite solar cells

“…On the other hand, the SEGIgated SCPs devices showed high charge mobilities compared to conventional OFETs with low-k poly(methyl methacrylate) (PMMA) dielectric. Fabricated homopolymer P0 and optimized P20 random copolymer SCPs PMMA-gated OFETs measured average hole mobility of 0.049 ± 0.003 and 0.065 ± 0.099 cm 2 V −1 second −1 , respectively, attributing to lower charge-carrier density despite the high driving voltage of −80 V. 46 Figure 4A shows the hole-only SCLC device architecture used for measuring the OOP charge-transporting abilities of the SCPs. 41,47 Furthermore, as shown in Figure 4B and Table 3, the random copolymers provided higher SCLC mobilities (μ h,SCLC ) than the homopolymer P0, which indicates that the random polymers provide an improved charge transport in the direction of OOP, owing to the increased randomness in the crystal orientations of their films ( Figure 2D).…”

Selenol-Based Nucleophilic Reaction for the Preparation of Reactive Oxygen Species-Responsive Amphiphilic Diblock Copolymers

“…Selenophene polymers have been considered to be effective photoelectric materials which may be widely used in solar cells, molecular switches, thin film transistors, etc. [4,5,6,7,8,9,10,11,12]. Diselenide-containing adaptive materials were successfully incorporated in the fabrication process under very mild conditions to achieve self-healing properties [13,14,15,16].…”