Bremen Center for Computational Materials Science, University of Bremen, Am Falturm 1, 28359, Bremen, Germany.
Nanoscale. 2013 Apr 21;5(8):3306-14. doi: 10.1039/c3nr33941f. Epub 2013 Mar 6.
Using density functional theory calculations, we show that recently synthesized carbon nanocomposites of graphene nanoribbons encapsulated in a carbon nanotube (GNR@CNT) possess rich emergent electronic and magnetic properties that offer new functionality and tunability and display systematic trends that are sensitive to the matchup of constitutive GNRs and CNTs. The encapsulation of H-passivated GNRs in metallic armchair CNTs always leads to a metallic complex while those in semiconducting zigzag CNTs can be either metallic or semiconducting depending on the chirality of GNRs. In particular, the complex of armchair GNRs in a zigzag CNT exhibits an oscillating electronic band gap with changing GNR width and a well-separated spatial distribution of electrons and holes localized in the CNT and GNR components, respectively. When bare large zigzag GNRs are encapsulated in an armchair CNT, the resulting complex shows strong structural stability and enhanced magnetism and, most interestingly, such GNR@CNT configurations can be tuned to be metallic or semiconducting depending on relative bond position and magnetic order. These results offer key insights for understanding and predicting emergent properties of GNR@CNT, which establish a roadmap for guiding design and synthesis of specific nanocomposite configurations with tailor-made properties for nanoelectronic, photovoltaic and spintronic applications.
利用密度泛函理论计算，我们表明，最近合成的石墨烯纳米带封装在碳纳米管中的碳纳米复合材料（GNR@CNT）具有丰富的新兴电子和磁性性质，提供了新的功能和可调性，并显示出对构成 GNR 和 CNT 的匹配敏感的系统趋势。在金属扶手椅 CNT 中封装 H 钝化 GNR 总是导致金属复合物，而在半导体锯齿形 CNT 中，GNR 的手性可以是金属或半导体。特别是，锯齿形 CNT 中扶手椅 GNR 的复合物表现出随 GNR 宽度变化的电子带隙的振荡，并且电子和空穴分别局域在 CNT 和 GNR 组件中的空间分布良好分离。当裸露的大锯齿形 GNR 被封装在扶手椅 CNT 中时，所得复合物表现出强结构稳定性和增强的磁性，并且最有趣的是，这种 GNR@CNT 配置可以根据相对键位置和磁序调谐为金属或半导体。这些结果为理解和预测 GNR@CNT 的新兴性质提供了关键的见解，为指导设计和合成具有特定纳米复合材料配置的纳米电子、光伏和自旋电子应用的定制性质的路线图奠定了基础。
