▎ 摘　　要

In this paper, the double-side contact (DSC) properties of CVD catalyst metals and graphene (Gr) are studied by first-principle methods. Our calculation shows that two special catalyst metals Pt and Ir would have extremely small contact resistances in DSC and the physical origination of such phenomenon is explicitly analyzed. Different from the common physisorption metal which would keep Gr's intrinsic conical dispersion, the simulation results of Pt and Ir in DSC show chemisorption characters due to the charge redistribution triggered exchange-transfer mechanism. The symmetry Pauli-exclusion and charge transfer effects in DSC complexes are found to play an important role in the intriguing transition. These results may bring new information to seek a suitable lead structure for 2D materials.