van der Waals epitaxy growth of monolayer copper telluride
Song-Fu Yao1,3*, Chia-Chun Chen1, Mario Hofmann2, Ya-Ping Hsieh3
1Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan
2Department of Physics, National Taiwan University, Taipei, Taiwan
3Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
* Presenter:Song-Fu Yao,
Few layer two-dimensional copper telluride is expected to be a potential candidate for spintronic, thermoelectric, and solar cells. However, the synthesis of copper telluride remains in bulk, and layer control of Cu2-xTe is still missing. It was recently found that 2D material grows on 2D material in high uniformity due to its dangling bond-free character. Therefore, we investigate the possibility of growing copper telluride on graphene/copper foil by chemical vapor deposition (CVD). The thickness controlling factor was studied through controlling the precursor concentration on the substrate. To achieve that, we introduce graphite as a diffusion barrier, resulting in a gradient distribution of the precursor concentration on the substrate. Consequently, we observe that copper telluride prefer to grow on the defect-free region of the graphene through van der Waals epitaxial mechanism, which is beneficial to a large area and uniform growth.

Keywords: 2D material, CVD, graphene, epitaxy, copper telluride