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).
