Atomic-precision Control of Single-crystalline 2D Materials & Recent Progress on Thin Film PV in IBM

Abstract: The fabrication of large-scale single-domain graphene is one of the most important research goals in the field of graphene research. Recently, we have developed a technique for fabricating an unprecedented form of a flat, single-oriented, monolayer graphene in a 4-inch wafer-scale. This graphene was proven to be cyrstallographically and electrically single-domain in a wafer-scale. The physics behind forming singlecrystalline graphene will be discussed. This single-crystalline graphene was used as a seed for growing single-crystalline films. We demonstrated direct van der Waals growth of high-quality single-crystalline films on this graphene with low defectivity. The single-crystalline film was then released precisely from a graphene surface and transferred onto Si substrates. The graphene/SiC substrate was reused for multiple growth and transfer cycles without any post-release surface treatment. I will talk about the detail of this process and how this accomplishment can be applied to current semiconductor research.I will also present our recent progress on fabricating high efficiency thin film solar cells including Cu2 ZnSn(S,Se)4 , amorphous silicon, and organic solar cells.