2D materials based on van der Waals heterostructures have remarkable applications in electronic de-vices. However, trapped contaminations between the interface heterostructure layers during fabrication pro-cesses degrade the device performance. Here, we report a novel fabrication method to prevent contamination of the device from air impurities to obtain atomically clean interfaces using an Argon shielding gas environment. Large-area graphene encapsulated with hexagonal boron nitride, approximately-12,637 & mu;m2, has been fabri-cated. Using the proposed methodology, high graphene mobility up to 600 000 cm2V- 1s- 1 at room temperature has been achieved. The theoretical analysis combined with a molecular dynamic simulation model was utilized to improve the dry transfer technique for large-scale fabrication of 2D materials.