2D materials based on van der Waals heterostructures have remarkable applications in electronic devices. However, trapped contaminations between the interface heterostructure layers during fabrication processes 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 μm2, has been fabricated. 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.