Abstract：
We demonstrate the key role of charge-transfer complexes in surface doping as a successful methodology for improving channel field-effect mobility and reducing the threshold voltage in organic field-effect transistors (OFETs), as well as raising the film conductivity. Demonstrated here for 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) doped with 2,2\'-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6TCNNQ), channel doping by sequential deposition is consistently rationalized by the development of a cocrystalline structure that forms and evolves from the surface of the organic semiconductor film without trading the thin-film structure integrity. This scenario brings higher benefits for the device operation than doping by codeposition, where a decrease in the field-effect mobility of the device, even for a dopant content of only 1 mol %, makes codeposition less suitable. Insight into the structural and electronic properties of the interface satisfactorily explains the improved performance of OFETs upon the incorporation of the dopant and provides an understanding of the mechanism of doping in this system.
摘要：
我们证明了电荷转移复合物在表面掺杂中的关键作用，作为一种成功的方法，可以提高沟道场效应迁移率并降低有机场效应晶体管（OFET）中的阈值电压。以及提高薄膜的导电性。此处证明了掺杂有2,2'-(全氟萘-2,6-二叉基)二丙二腈(F6TCNNQ)的2,7-二辛基[1]苯并噻吩并[3,2-b][1]苯并噻吩(C8-BTBT)，通过顺序沉积的沟道掺杂通过共晶结构的发展始终合理化，该共晶结构从有机半导体膜的表面形成和演变而不交换薄膜结构的完整性。与通过共沉积掺杂相比，这种情况为器件操作带来了更高的好处，其中器件的场效应迁移率降低，即使掺杂剂含量仅为1摩尔%，使共沉积不太合适。对界面的结构和电子特性的洞察令人满意地解释了OFET在掺入掺杂剂后的性能改善，并提供了对该系统中掺杂机理的理解。
