The effects of the molecular structure of thiazole-based polymers on the active layer morphologies and performances of electronic and photovoltaic devices were studied. Thus, thiazole-based conjugated polymers with a novel thiazole-vinylene-thiazole (TzVTz) structure were designed and synthesized. The TzVTz structure was introduced to extend the π conjugation and coplanarity of the polymer chains.
View Article and Find Full Text PDFElectrohydrodynamic-jet (EHD-jet) printing provides an opportunity to directly assembled amorphous polymer chains in the printed pattern. Herein, an EHD-jet printed amorphous polymer was employed as the active layer for fabrication of organic field-effect transistors (OFETs). Under optimized conditions, the field-effect mobility (μ) of the EHD-jet printed OFETs was 5 times higher than the highest μ observed in the spin-coated OFETs, and this improvement was achieved without the use of complex surface templating or additional pre- or post-deposition processing.
View Article and Find Full Text PDFCharge carriers typically move faster in crystalline regions than in amorphous regions in conjugated polymers because polymer chains adopt a regular arrangement resulting in a high degree of π-π stacking in crystalline regions. In contrast, the random polymer chain orientation in amorphous regions hinders connectivity between conjugated backbones; thus, it hinders charge carrier delocalization. Various studies have attempted to enhance charge carrier transport by increasing crystallinity.
View Article and Find Full Text PDFA 50 nm-wide 6,13-bis(triisopropylsilylethynyl) pentacene nanowire (NW) array is fabricated on a centimeter-sized substrate via a facile nanograting-assisted pattern-transfer method. NW growth under a nanoconfined space adopts a lattice-strained packing motif of the NWs for strong intermolecular electronic coupling, and thus a NW-based organic field-effect transistor shows high field-effect mobility up to 9.71 cm(2) V(-1) s(-1) .
View Article and Find Full Text PDFComplementary inverters consisting of p-type organic and n-type metal oxide semiconductors have received considerable attention as key elements for realizing low-cost and large-area future electronics. Solution-processed ZnO thin-film transistors (TFTs) have great potential for use in hybrid complementary inverters as n-type load transistors because of the low cost of their fabrication process and natural abundance of active materials. The integration of a single ZnO TFT into an inverter requires the development of a simple patterning method as an alternative to conventional time-consuming and complicated photolithography techniques.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2015
We report six asymmetric alkylated anthracene-based molecules with different alkyl side chain lengths for use in organic field-effect transistors (OFETs). Alkyl side chains can potentially improve the solubility and processability of anthracene derivatives. The crystallinity and charge mobility of the anthracene derivatives may be improved by optimizing the side chain length.
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