Percolation behaviour in high mobility p-channel polymer/small-molecule blend organic field-effect transistors
Percolation behaviour in high mobility p-channel polymer/small-molecule blend organic field-effect transistors
复制标题
DOI：
10.1016/j.orgel.2010.10.017
复制
发表时间：
2011
影响因子：
3.2
通讯作者：
Jeremy Smith;M. Heeney;I. McCulloch;J. N. Malik;N. Stingelin;D. Bradley;T. Anthopoulos
中科院分区：
文献类型：
--
作者：
Jeremy Smith;M. Heeney;I. McCulloch;J. N. Malik;N. Stingelin;D. Bradley;T. Anthopoulos
基于2,8-二氟-5,11-双（三乙基硅乙基）反辐射噻吩（diF-TES ADT）和聚（三芳胺）[PTAA]共混物的有机晶体管由于其破纪录的载流子迁移率和环境稳定性，在未来的大批量有机电子中具有很强的应用前景。在这里，我们报告了空穴输运对diF-TES ADT:PTAA共混物组成的依赖。只有在含有大于或等于39 wt.% diF-TES ADT的混合物中才能获得最大迁移率。在低于这个阈值的组合物中，空穴迁移率急剧降低，并且与整齐聚合物基体（即PTAA）的空穴迁移率相等（~ 10−3cm2/Vs）。扫描原子力和偏振光显微镜，结合差示扫描量热法，表明这个阈值对应于晶体的出现，在这种混合膜中富含苯乙烯的区域，以及在源极和漏极之间形成高迁移率的传导途径。孔迁移率对diF-TES ADT浓度的依赖性可以用简单的渗流模型来模拟。目前的结果为这种高性能半导体共混物的微观结构演变提供了重要的见解，并可能证明对下一代有机晶体管的开发有价值。
Organic transistors based on blends of 2,8-difluoro-5,11-bis(triethylsilylethynyl) anthradithiophene (diF-TES ADT) and poly(triarylamine) [PTAA] are strong candidates for application in future large-volume organic electronics because of their record breaking carrier mobility and environmental stability. Here we report on the dependence of hole transport on the composition of diF-TES ADT:PTAA blends. Maximum mobility is obtained only for blends containing⩾39 wt.% diF-TES ADT. At compositions below this threshold the hole mobility is drastically reduced and is found to be equal to that of the neat polymer matrix, i.e. PTAA (∼10−3cm2/Vs). Scanning atomic force and polarised light microscopy, combined with differential scanning calorimetry, show that this threshold corresponds to the appearance of crystalline, acene-rich regions in such blend films, and the formation of high mobility conduction pathways between the source and drain electrodes. The dependence of hole mobility on diF-TES ADT concentration can be modelled using a simple percolation model. The present results provide important insights into the microstructure evolution in this high performance semiconducting blend and could prove valuable for the development of the next generation organic transistors.