Department of Materials Science and Engineering, Izmir Institute of Technology, 35430 Urla, Izmir, Turkey.
Catalan Institute of Nanoscience and Nanotechnology, CSIC and The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Barcelona, Spain.
Nano Lett. 2022 Mar 23;22(6):2202-2208. doi: 10.1021/acs.nanolett.1c03883. Epub 2022 Mar 1.
In the context of graphene-based composite applications, a complete understanding of charge conduction in multilayer reduced graphene oxides (rGO) is highly desirable. However, these rGO compounds are characterized by multiple and different sources of disorder depending on the chemical method used for their synthesis. Most importantly, the precise role of interlayer interaction in promoting or jeopardizing electronic flow remains unclear. Here, thanks to the development of a multiscale computational approach combining first-principles calculations with large-scale transport simulations, the transport scaling laws in multilayer rGO are unraveled, explaining why diffusion worsens with increasing film thickness. In contrast, contacted films are found to exhibit an opposite trend when the mean free path becomes shorter than the channel length, since conduction becomes predominantly driven by interlayer hopping. These predictions are favorably compared with experimental data and open a road toward the optimization of graphene-based composites with improved electrical conduction.
在基于石墨烯的复合材料应用中,全面了解多层还原氧化石墨烯(rGO)中的电荷传导是非常可取的。然而,这些 rGO 化合物的特点是具有多种不同的无序来源,具体取决于用于合成它们的化学方法。最重要的是,层间相互作用在促进还是破坏电子流动方面的精确作用仍不清楚。在这里,由于开发了一种多尺度计算方法,将第一性原理计算与大规模输运模拟相结合,多层 rGO 中的输运标度定律被揭示出来,解释了为什么扩散随着膜厚度的增加而恶化。相比之下,当平均自由程短于通道长度时,接触的薄膜被发现表现出相反的趋势,因为传导主要由层间跳跃驱动。这些预测与实验数据吻合良好,并为优化具有改善电传导性能的基于石墨烯的复合材料开辟了道路。