Fluorinated Dithienylethene–Naphthalenediimide Copolymers for High-Mobility n-Channel Field-Effect Transistors

Abstract

We develop two donor−acceptor copolymers based on a fluorinated dithienylethene building block, namely PNFDTE1 and PNFDTE2, in which naphthalenediimide (NDI) acts as an acceptor unit. Thermogravimetric analysis displayed both copolymers having good thermal stability with high decomposition temperatures over 400 °C. Broad absorption spectra were observed in the UV−vis−NIR region, with the absorption maxima being 720 and 724 nm for PNFDTE1 and PNFDTE2, respectively. Cyclic voltammetry tests exhibited deep-lying lowest unoccupied molecular orbital energy levels of ca. −4.0 eV. Twodimensional grazing incidence X-ray diffraction patterns showed that different packing modes for two polymers result in the variation in charge transport properties. Backbone fluorination effectively decreases electron injection barrier, thereby facilitating electron mobility. An impressive electron mobility of 3.20 cm 2 V −1 s −1 was achieved in air for PNFDTE1-based polymer field-effect transistors fabricated on the poly(ethylene terephthalate) substrate. The mobility value is almost the highest for NDI-containing polymers on the flexible substrate. This work provides a guideline for design and synthesis of fluorinated semiconductors that enables control of chargetransport polarity.

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

“…Chen et al copolymerized the NDI units with fluorinated TVT units ( P34 ). The lowered LUMO energy level of P34 was contributed to the strong electron‐withdrawing ability of fluorine, and P34 ‐based OFETs exhibited a μ e value of 3.20 cm 2 V −1 s −1 …”

Concurrent Optical Gain Optimization and Electrical Tuning in Novel Oligomer:Polymer Blends with Yellow‐Green Laser Emission

“…For this purpose we introduce three novel largely steric oligomer hosts with various side substituents, 9-octyl-3,6-bis (2,7,9-triphenyl-9H-fluoren-9-yl)-9H-carbazole (DPHS), 3,6-bis(2,7-bis(3,5-difluorophenyl)-9-phenyl-9H-fluoren-9-yl)-9-octyl-9H-carbazole (DF), and 3,6-bis(2,7bis(3,5-bis(trifluoromethyl)phenyl)-9-phenyl-9H-fluoren-9-yl)-9-octyl-9H-carbazole (DCF3). [30,31] These oligomers all share similar properties regardless their side substituents: they possess deep-blue fluorescence, relatively high PLQE, and outstanding thermal stability with T d and T g temperatures exceeding 380 and 150 °C, respectively (see Figure S2, Supporting Information). Cyclic voltammograms ( Figure S1, Supporting Information) demonstrate that fluorination induces an increase in electron affinity and ionization potential values of 0.35 and 0.2 eV owing to the high fluorine electronegativity and the strong dipole moment associated to the CF bond.…”

Ultraviolet Photodetecting and Plasmon-to-Electric Conversion of Controlled Inkjet-Printing Thin-Film Transistors

“…Of most interest is that the O 1s peak at the surface that was consistently fitted by a Lorentzian-Gaussian function, and the components of O I , O II , and O III were centered at~530.6,~531.9, and~532.4 eV, respectively. The component O III at the high binding energy located at 532.4 eV is mainly due to the presence of loosely bound oxygen on the surface of the ZnO film, such as -CO 3 Figure S4) on the binding energies of the Zn 2p 3/2 and Zn 2p 1/2 components were centered at~1021.4 and~1044.5 eV, respectively. This is because the oxygen O 2 treatment primarily improves the surface quality of ZnO film, but has no significant effect on their microstructure and crystallinity [39].…”

“…Over the past decade, field-effect transistors (FETs) and thin-film transistors (TFTs) based on organic and inorganic materials have been widely developed for advanced applications, such as flat-panel displays for realizing high-resolution displays. The advantages of TFTs based on metal-oxide-based materials include high electron mobility, thermal stability and stable electrical characteristics [1][2][3][4][5][6]. Recently, solution processing methods under low temperatures of 200-300 • C have attracted much interest for fabricating metal-oxide-based TFTs.…”