High performance transistors based on the controlled growth of triisopropylsilylethynyl-pentacene crystals via non-isotropic solvent evaporation
High performance transistors based on the controlled growth of triisopropylsilylethynyl-pentacene crystals via non-isotropic solvent evaporation
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DOI：
10.1039/c4ra02300e
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发表时间：
2014-01-01
期刊：
影响因子：
3.9
通讯作者：
Logothetidis, S.
中科院分区：
文献类型：
--
作者：
Pitsalidis, C.;Kalfagiannis, N.;Logothetidis, S.
三异丙基硅基乙炔基并五苯（TIPS-PEN）由于其在稳定性、性能和易加工性方面的独特特性而被证明是分子电子学领域中最有前途的小分子之一。在广泛的用于沉积TIPS-PEN的各种成熟技术中，叶片计量法最近对于在大面积上形成均匀的结晶膜获得了极大的兴趣。根据这一基本原理，我们在此设计了一种基于刮刀涂布的通用方法，该方法通过操纵溶剂蒸发行为以带来优先程度的晶体取向的方式克服了各向异性晶体形成的问题。通过在玻璃上以及在二氧化硅/硅（SiO2/Si）衬底上制造场效应晶体管来评估该方法的适用性。有趣的是，在试图改善SiO2/Si基板上的液体膜的流变性和润湿行为，我们引入了聚苯乙烯（PS）或聚甲基丙烯酸甲酯（PMMA）的聚合物中间层，同时作为钝化和结晶辅助层。在这种情况下，高度有序的晶体结构和氧化物表面改性的协同效应进行了彻底的研究。所制备的器件的整体性能显示出优异的电学特性，具有高达0.72 cm（2）V-1 s（-1）的高饱和迁移率（在具有聚合物电介质的玻璃上），开/关电流比>10（4）和低阈值电压值（
Triisopropylsilylethynyl-pentacene (TIPS-PEN) has proven to be one of the most promising small molecules in the field of molecular electronics, due to its unique features in terms of stability, performance and ease of processing. Among a wide variety of well-established techniques for the deposition of TIPS-PEN, blade metered methods have recently gained great interest towards the formation of uniform crystalline films over a large area. Following this rationale, we herein designed a versatile approach based on blade-coating, which overcomes the problem of anisotropic crystal formation by manipulating the solvent evaporation behaviour, in a way that brings about a preferential degree of crystal orientation. The applicability of this method was evaluated by fabricating field-effect transistors on glass as well as on silicon dioxide/silicon (SiO2/Si) substrates. Interestingly, in an attempt to improve the rheological and wetting behaviour of the liquid films on the SiO2/Si substrates, we introduced a polymeric interlayer of polystyrene (PS) or polymethylmethacrylate (PMMA) which concurrently acts as passivation and crystallization assisting layer. In this case, the synergistic effects of the highly-ordered crystalline structure and the oxide surface modification were thoroughly investigated. The overall performance of the fabricated devices revealed excellent electrical characteristics, with high saturation mobilities up to 0.72 cm(2) V-1 s(-1) (on glass with polymeric dielectric), on/off current ratio >10(4) and low threshold voltage values (