Conductivity Modifications of Graphene by Electron Donative Organic Molecules
Conductivity Modifications of Graphene by Electron Donative Organic Molecules
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DOI：
10.1007/s11664-017-5392-1
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发表时间：
2017-03
影响因子：
2.1
通讯作者：
Hiroaki Masujima;Takehiko Mori;Y. Hayamizu
中科院分区：
文献类型：
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作者：
Hiroaki Masujima;Takehiko Mori;Y. Hayamizu
石墨烯已被研究用于透明电极在半导体有机柔性电子器件中的应用。控制石墨烯中的载流子密度对于降低石墨烯与有机半导体有源层之间的接触电阻至关重要。石墨烯的化学掺杂是一种改变载流子密度的方法，其中被吸附的有机分子从石墨烯中捐赠或接受电子。虽然目前已经发现了各种各样的受体有机分子，但对供体分子的研究仍然很少。在这项工作中，我们研究了由有机供体分子如二苯并四噻吩戊烯（DBTTF）、六甲基四噻吩戊烯（HMTTF）、1,5-二氨基萘（DAN）和N，N,N ',N ' -四甲基对苯二胺（TMPD）功能化的石墨烯场效应晶体管中的掺杂效应。通过对石墨烯晶体管电导率的测量，发现前三种分子对石墨烯晶体管的电导率没有显著影响。然而，TMPD表现为有效型掺杂。掺杂效应与各分子的最高已占据分子轨道（HOMO）能级有关，其中TMPD的HOMO能级最高。
Graphene has been studied for the application of transparent electrodes in flexible electrical devices with semiconductor organics. Control of the charge carrier density in graphene is crucial to reduce the contact resistance between graphene and the active layer of organic semiconductor. Chemical doping of graphene is an approach to change the carrier density, where the adsorbed organic molecules donate or accept electrons form graphene. While various acceptor organic molecules have been demonstrated so far, investigation about donor molecules is still poor. In this work, we have investigated doping effect in graphene field-effect transistors functionalized by organic donor molecules such as dibenzotetrathiafulvalene (DBTTF), hexamethyltetrathiafulvalene (HMTTF), 1,5-diaminonaphthalene (DAN), andN,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD). Based on conductivity measurements of graphene transistors, the former three molecules do not have any significant effect to graphene transistors. However, TMPD shows effectiven-type doping. The doping effect has a correlation with the level of highest occupied molecular orbital (HOMO) of each molecule, where TMPD has the highest HOMO level.