Unintentional doping induced splitting of G peak in bilayer graphene

Abstract

Raman characterizations show the G peak of an unintentional doped single crystal bilayer graphene (BLG) splits into two peaks: S and AS peaks. From the relative shift between S and AS peaks, the doping concentration is estimated to be from 8.8 × 1012 cm−2 to 2 × 1013 cm−2, as in the same order of that in monolayer graphene prepared under the same condition. The dopants distribute relatively homogeneously in a 0.7 mm× 0.3 mm large BLG judged through the G peak splitting. The 2D peak of heavy doped BLG can only be deconvoluted into three peaks, corresponding to 2D1B, 2D1A, and 2D2A peaks.