Graphene—the one-atom-thick sheet of carbon—is the most famous of 2D materials due to its unique electronic properties and mechanical strength. However, its chemical inertness makes graphene also an excellent nearly electron-transparent support for other materials and nanostructures. In this presentation, I will give an overview of our recent work enabled by a unique interconnected vacuum system containing an aberration-corrected scanning transmission electron microscope Nion UltraSTEM 100 with a unique objective area that allows sample cleaning via laser, in situ chemical experiments, and direct vacuum transfer to an atomic force microscope (AFSEM by GeTEC Microscopy), to-and-from an argon glove box, target chamber with a plasma ion source and evaporators, and long term vacuum sample storage. In brief, I will demonstrate that defect-engineering of graphene  enables its substitutional heteroatom doping  and growth of nanoclusters with a well-defined concentration and a narrow size distribution, as well as the direct correlation of its atomic structure and mechanical properties. I will further show that graphene can be used as a support for the growth of 2D CuAu  and describe the first steps of the growth of Ti on graphene . Finally, I will provide examples of otherwise unstable structures being stabilized in the van der Waals gap between two graphene sheets, including a mono-layer of fullerenes , 2D CuI  and small noble gas clusters .
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