Fig. 1

Graphene–tin nanoislands hybrid system on 4 inch intrinsic germanium wafer. a Sketch illustration of the designed system consisting of tin nanoislands-decorated single crystalline monolayer graphene. b Atomic force microscopy (AFM) image of discontinuous tin islands with a uniform thickness of 10 nm self-assembled on single crystalline graphene. The scale bar is 500 nm. Inset: The depth profile along the white dash line in Fig. 1b. c STEM image of the cross sectional 10 nm-thick discontinuous tin-nanoislands on the graphene, and the corresponding STEM-EDS mapping images revealing the distributions of Sn and Ge. The scale bar is 100 nm. d Photograph of the test device matrixes fabricated on 4 inch intrinsic germanium wafer. e Magnified view from d shows nine individual superconducting devices assembled into one array. The scale bar is 2 mm