Tuning the electrical properties of exfoliated graphene layers using deep ultraviolet irradiation

It is possible to tune the electrical properties of graphene layers in graphene-based nanoelectronic and optoelectronic devices while maintaining their unique band structure and electrical properties. We report here the use of deep ultraviolet irradiation (DUV) to tune the electronic properties of mechanically exfoliated single-layer graphene (SLG), bilayer graphene (BLG), and trilayer graphene (TLG). Raman spectroscopy and electrical transport measurements showed that DUV imposes p-doping on SLG, BLG, and TLG devices. The shift in the G and 2D peak wave numbers and intensity ratios of SLG, BLG, and TLG devices were examined as a function of irradiation time. Analysis of the shift in the Dirac points as a function of irradiation time indicated the p-type doping effect for all SLG, BLG, and TLG devices. This investigation has shown that DUV irradiation is a non-destructive approach which can be used to tailor the electrical properties of SLG, BLG, and TLG while maintaining their important structural and electrical characteristics.