Dear Dr. Salvatore Croce

Graphene/hexagonal boron nitride (h-BN) heterostructures have been widely studied in recent years due to their excellent properties (thermal conductivity, smooth surface roughness ...) especially the electron mobility which is very important in electronics based devices. I think that the electron mobility in graphene on h-BN transistors reaches 6 eV. The surface roughness of graphene on (h-BN) is estimated around 0.21 nm.

Article Graphene on Hexagonal Boron Nitride

Article Two-Dimensional Semiconductor Optoelectronics Based on van d...

Ok, thank you. Would you know also papers on more high impact factor journals? What is the situation on other substrates? Anyway what I meant was what happens if someone twists the graphene layer respect to the underlying hexagonal lattice

In general, across 2D materials and carbon-like materials (graphene, graphite, diamond...) phonon transport predominate the heat conduction. Graphene is compound by a lattice of hexagonally carbon atoms. In nanomaterials, phonons collisions (interactions) represents a key role to understand such physical properties (thermal conductivity, heat capacity, electron mobility…).

• Article Thermal Properties of Graphene: Fundamentals and Applications

• https://www.nature.com/articles/nmat3064

• Article Effective Cleaning of Hexagonal Boron Nitride for Graphene Devices

• Article High Velocity Saturation in Graphene Encapsulated by Hexagon...

Yes, I know there is ballistic conduction in graphene (it was my master project, with e-ph interaction with Feynman diagrams), thanks. Further in graphene you have acoustical and optical phonons (which are quantum lattice vibrations by the way). You find more here: 10.1103/RevModPhys.81.109 . As I wrote I was just asking if you could improve the electronic properties with different angles of deposition.

Thank you, it is very important paper.

The ballistic-diffusive transport is the subject of my thesis. Also in my work i try to enhance the electronic and thermal properties across nanodevices. about your question the angle varied with phonon mean free path (MFP) and edge the roughness. This angle is determinated by the atomic force microscopy (ATM) measurement. I recomond this paper :

Article Anomalous Size Dependence of the Thermal Conductivity of Gra...

and my recent work :

Article Investigation of heat transport across Ge/Si interface using...