Dopants, i.e., electronically active impurities, are added to organic semiconductor materials to control the material's Fermi level and conductivity, to improve injection at the device contacts, or to fill trap states in the active device layers and interfaces. In contrast to bulk doping as achieved by blending or co‐deposition of dopant and semiconductor, surface doping has a lower propensity to introduce additional traps or scattering centers or to even alter the layer morphology relative to the undoped active material layers. In this study, the electrical effects of a very simple, post‐device‐fabrication surface doping process involving various amine group–containing alkoxysilanes on the performance of organic field‐effect transistors (OFETs) made from the well‐known n‐type materials PTCDI‐C8 and N2200 are researched. It is demonstrated that OFETs doped in such a way generally show enhanced characteristics (up to 10 times mobility increase and a significant reduction in threshold voltage) without any adverse effects on the devices' on/off ratio. It is also shown that the efficiency of the doping process is linked to the number of amine groups.

中文翻译：

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通过氨基硅烷表面掺杂增强n型有机场效应晶体管的性能

将掺杂剂（即电子活性杂质）添加到有机半导体材料中，以控制材料的费米能级和电导率，改善器件接触处的注入或填充有源器件层和界面中的陷阱态。与通过掺杂剂和半导体的混合或共沉积实现的体掺杂相比，表面掺杂相对于未掺杂的活性材料层，具有较低的倾向来引入额外的陷阱或散射中心，甚至改变层的形态。在这项研究中，涉及多种含胺基的烷氧基硅烷的非常简单的设备制造后表面掺杂工艺的电效应对由著名的n型材料PTCDI制成的有机场效应晶体管（OFET）的性能的影响对C8和N2200进行了研究。已经证明，以这种方式掺杂的OFET通常显示出增强的特性（高达10倍的迁移率增加和阈值电压的显着降低），而对器件的开/关比没有任何不利影响。还显示出掺杂过程的效率与胺基团的数目有关。