Many of today's silicon-based electronic components contain 2D materials such as graphene. Incorporating 2D materials like graphene — which is composed of a single-atom-thick layer of carbon atoms — into these components allows them to be several orders of magnitude smaller than if they were made with conventional 3D materials. In addition, 2D materials also enable other unique functionalities. But nanoelectronic components with 2D materials have an Achilles’ heel — they are prone to overheating. This is because of poor heat conductance from 2D materials to the silicon base.
One of the reasons 2D materials can't efficiently transfer heat to silicon is that the interactions between the 2D materials and silicon in components like transistors are rather weak. Bonds between the 2D materials and the silicon substrate are not very strong, so when heat builds up in the 2D material, it creates hot spots, causing overheating and device failure.
In order to enhance the connection between the 2D material and the silicon base to improve heat conductance away from the 2D material into the silicon, engineers have experimented with adding an additional ultra-thin layer of material on top of the 2D layer — in effect, creating a “nano-sandwich” with the silicon base and ultrathin material as the “bread.” Sandwiching 2D materials used in nanoelectronic devices between their 3D silicon bases and an ultrathin layer of aluminum oxide can significantly reduce the risk of component failure due to overheating.
An experimental transistor was created using silicon oxide for the base, carbide for the 2D material, and aluminum oxide for the encapsulating material. At room temperature, the conductance of heat from the carbide to the silicon base was twice as high with the addition of the aluminum oxide layer versus without it.