The most appropriate material for a sacrificial (protection) layer to effectively stop an irradiated ion in 2D materials supported on the surface of a SiO 2 substrate was explored for changing the structure, electronic properties, and chemical activities of 2D materials by ion-implantation. We found that a NaCl protection layer covered by a Cr layer is the most suitable sacrificial layers for graphene, MoS 2 , and TaS 2 based on Raman spectroscopy and electron transport properties. The gate voltage dependence of the conductivity (resistivity) shows that irradiating graphene with B and N ions at 200 keV with a dose of 10 13 cm −2 using a Cr or NaCl sacrificial layer, introduces hole and electron carriers, respectively. Both the B and N atoms introduced by ion beam irradiation cause strain in the graphene lattice, resulting in it partially detaching from the substrate like quasi-freestanding graphene. Irradiation with B ions creates neutral impurities in graphene, producing stronger carrier scattering in the Raman scattering, and irradiation with N ions creates charged impurities which affect electron transport phenomena, respectively. The developed sacrificial layers are promising for the defect engineering of 2D materials.

No abstract