Van der Waals materials (vdW), such as graphene and transition metal dichalcogenides (TMDs), have attracted remarkable attention due to their thickness-dependent electrical, optical and thermal properties. Since the discovery of superconductivity in twisted bilayer graphene stacked at a precise ‘magic’ angle of 1.1 degrees, the relative layer orientation is considered a new degree of freedom in material design. Therefore, in vdW systems, atomic precision control can be achieved in both the number of layers and their relative orientation. As a consequence, by precisely controlling the twist angle between the layers of 2D materials, we can obtain new, multi-functional materials tailored for specific applications.

Since it is known that more than 50% of failures of electronic devices are related to overheating, novel 2D materials are already envisaged and actively investigated to advance 3D integration, and these include graphene and TMDCs. In this project, anisotropic thermal conductors will be realised to guide heat flow in a given direction. In practice, this would mean that heat will be evacuated from hotspots only through a predefined path without affecting adjacent structures and sensitive components, a functionality which is currently very limited and far below requirements with the standard heat spreading materials. We will investigate 2D materials and their heterostructures assembled with atomic precision targeting specific angles in order to modify their phononic properties thereby achieving a strong elastic and thermal conductivity anisotropy, which is a condition towards reliable electronic components, circuits and systems.