Two Dimensional Performance with Three Dimensional Capacity: Engineering the Thermal Properties of Graphene

本程序的目的是研究旋转角对扭曲的双层石墨烯导热系数的影响。实验和理论证据都清楚地表明，扭曲双层石墨烯中各层的电子态是解耦的。扭角对声子色散的影响仍然是一个悬而未决的问题，扭角对面内热输运的影响还有待研究。这些问题是密切相关的，因为热是由声子携带的。如果扭转石墨烯层中的声子耦合被抑制，那么多层扭转石墨烯薄膜将提高单个2D层的平行作用的导热系数，从而允许超大热流密度的传递。这个程序的智能优点在于创造了基础知识，确定了扭角与双层石墨烯导热系数的关系。通过使用错位堆积来保持块状材料中石墨烯的2D性质的可能性是一个变革性的概念，它给了我们两个世界的最好的？2D的增强性能与3D的能力相结合。更广泛的影响该项目包括石墨烯在热管理方面的新应用。它具有提高美国技术竞争力的潜力。它将增加女性和代表不足的少数族裔的参与，并为加州大学河滨分校的本科生和研究生STEM教育做出贡献，这是加州大学所有校园中拉美裔学生人数最多的少数族裔服务机构。该项目由电子、通信和网络系统司(ECCS)的电子、光子学和磁性设备计划(EPMD)和材料研究部(DMR)的电子和光子材料计划(EPM)共同资助。

The objective of this program is to investigate the effect of rotation angle on the thermal conductivity of twisted bilayer graphene. The experimental and theoretical evidence is clear that the electronic states of the individual layers in twisted bilayer graphene are decoupled. The effect of the twist angle on the phonon dispersion is still an open question, and the effect of twist angle on the in-plane thermal transport has yet to be studied. These questions are intimately related since the heat is carried by the phonons. If the phonon coupling in twisted graphene layers were suppressed, then the multi-layer twisted graphene films would have enhanced thermal conductivity of single 2D layers acting in parallel, thus allowing for transfer of extraordinary large heat fluxes. The intellectual merit of this program is in creating fundamental knowledge determining the relation of twist angle to the thermal conductivity of bilayer graphene. The possibility of maintaining 2D properties of graphene in bulk materials through the use of misoriented stacking is a transformational concept giving us the best of both worlds ? the enhanced performance of 2D combined with the capacity of 3D.The broader impact the project includes new applications of graphene for thermal management. It has the potential to increase the US technological competitiveness. It will increase the participation of women and underrepresented minorities and contribute to undergraduate and graduate STEM education at UC Riverside, which is the minority serving institution with the largest Hispanic student population among all UC campuses. This project is jointly funded by the Electronics, Photonics, and Magnetic Devices Program (EPMD) in the Division of Electrical, Communications and Cyber Systems (ECCS) and by the Electronic and Photonic Materials Program (EPM) in the Division of Materials Research (DMR).