有機半導體溶液製程沉積方法提供有前景的技術來製造大面積，低成本和彈性的有機電子元件。本研究報告了通過剪切力塗佈法方法及分子設計工程增強n通道有機薄膜電晶體管 (Organic Thin Film Transistor; OTFT) 性能的策略。我們使用下列四種具有不同烷基側鍊長度的二氰基亞甲基取代的醌型二噻吩噻吩(DTDSTQ)為核心的新型有機半導體的新型材料系列: (1)DTDSTQ-6 (硫代己基)，(2)DTDSTQ-10 (硫代癸基)，(3)DTDSTQ-14 (硫代十四烷基)，並且在烷基側餾分中不引入硫 (4)DTDRTQ-14 (十四烷基)。從DFT計算和單晶X光射線衍射獲得的優化的幾何結果顯示了DTDSTQ的高核平面性。 DTDSTQ核心以面對面的π-π堆疊佈置堆疊，堆疊距離為3.42 Å，短分子間S-N距離為3.56 Å，形成二維網絡電荷傳輸。更進一步結合2D-GIXRD分析，知道有機分子側立於基板上。高核平面性和非常低 -4.2 eV的LUMO能階有利的分子組裝，也表明DTDSTQ可能是新型有前景的n型有機半導體材料。對這些新化合物的物理，電化學以及電學性質進行了深入研究。通過溶液剪切力塗佈的DTDSTQ-14實現了高達0.41 cm2V-1s-1的最高電子遷移率，具有至少1個月的良好熱穩定性。結果表明，通過側鏈基工程可以改善剪切DTDSTQ的元件性能。 ;Solution-processable organic semiconductor deposition methods show promising technologies to fabricate large-area, low-cost and flexible organic electronics. This study reports the strategy for enhancing n-channel organic thin film transistors (OTFTs) performance by molecular design engineering through solution-shearing method. New series of organic semiconductor materials based small molecules with the core of dicyanomethylene-substituted quinoidal dithioterthiophene (DTDSTQ) modified by different alkyl side chain length: (1)DTDSTQ-6 (thio-hexyl), (2)DTDSTQ-10 (thio-decyl), (3)DTDSTQ-14 (thio-tetradecyl) and without sulfur introduction in alkyl side moiety: (4)DTDRTQ-14 (tetradecyl) were used. Optimized geometry obtained from DFT calculation and single-crystal X-ray diffraction reveals the high core planarity of DTDSTQ. The DTDSTQ core packed in a face-to-face slipped π-π stacking arrangement, with short stacking distance of 3.42 Å and short intermolecular S – N distance of 3.56 Å, forming 2-dimensional network charge transport. Further investigation with 2D-GIXRD analysis reveal that molecules packed edge-on to the substrate. The favorable molecular packing, the high core planarity and very low LUMO energy level of -4.2 eV suggesting that DTDSTQs could be a promising new n-type organic semiconductor materials. The physical, electrochemical as well as electrical properties of these new compounds are thoroughly investigated. The highest electron mobility of up to 0.41 cm2 V-1 s-1 with good thermal stability for at least 1 month was achieved by solution-sheared DTDSTQ-14. The results show that the device performance of solution-sheared DTDSTQs can be improved by side chain engineering.
