Giant enhancement in vertical conductivity of stacked CVD graphene sheets by self-assembled molecular layers
Giant enhancement in vertical conductivity of stacked CVD graphene sheets by self-assembled molecular layers
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DOI：
10.1038/ncomms6461
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发表时间：
2014-11-01
影响因子：
16.6
通讯作者：
Loh, Kian Ping
中科院分区：
文献类型：
--
作者：
Liu, Yanpeng;Yuan, Li;Loh, Kian Ping
逐层堆叠的化学气相沉积（CVD）石墨烯膜在太阳能电池、有机发光二极管和触摸面板中用作透明和导电电极。与具有各向异性电子离域的层状型系统相同，这种系统中的平面到平面（垂直）电导率比其平面内电导率低几个数量级。平面之间的电子耦合较差是由于转移过程中存在有机残留物和皱纹中的气穴。在这里，我们表明堆叠的CVD石墨烯层的平面到平面隧穿导电性可以通过在石墨烯层之间插入1-芘丁酸N-羟基琥珀酰亚胺酯来显著改善。平面到平面电导率的六个数量级的增加是由于空穴掺杂、轨道杂化、平面化和聚合物残留物的排除。我们的研究结果强调了界面改性对提高LBL堆叠CVD石墨烯膜性能的重要性，这应该适用于其他类型的堆叠二维膜。
Layer-by-layer-stacked chemical vapour deposition (CVD) graphene films find applications as transparent and conductive electrodes in solar cells, organic light-emitting diodes and touch panels. Common to lamellar-type systems with anisotropic electron delocalization, the plane-to-plane (vertical) conductivity in such systems is several orders lower than its in-plane conductivity. The poor electronic coupling between the planes is due to the presence of transfer process organic residues and trapped air pocket in wrinkles. Here we show the plane-to-plane tunnelling conductivity of stacked CVD graphene layers can be improved significantly by inserting 1-pyrenebutyric acid N-hydroxysuccinimide ester between the graphene layers. The six orders of magnitude increase in plane-to-plane conductivity is due to hole doping, orbital hybridization, planarization and the exclusion of polymer residues. Our results highlight the importance of interfacial modification for enhancing the performance of LBL-stacked CVD graphene films, which should be applicable to other types of stacked two-dimensional films.