Changing the structural and electronic properties of graphene and related two-dimensional materials using ion beam irradiation with NaCl sacrificial layers

Abstract

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.

Functionalization of graphene for precise control of the structure and electronic properties of carbon materials

“…The electronic properties of real carbon materials composed of nonideal graphene structures are complex and difficult to under- ficial layers that could be removed after ion-beam irradiation and did not damage the graphene during the formation process [17].…”