▎ 摘　　要

A Raman study of a twisted bilayer graphene grown by chemical vapor deposition (CVD) and transferred on SiO2 substrate is presented. The Raman spectra show the G and 2D peaks at 1582 cm(-1) and 2683 cm(-1) respectively. The presence of the interlayer Raman band (I band) in the range 1374 cm(-1) - 1440 cm(-1) and of the R band at 1484 cm(-1), as well as the single-Lorentzian line shape of the 2D peak, reveals the incommensurate stacking of the two graphene layers. From the R band, we determined that the twist angle (theta = 13.9 degrees) is close to the critical angle theta(c) (11.9 degrees for the excitation photon energy of 233 eV). The effect of annealing at 1050 degrees C of the incommensurate twisted bilayer graphene (ItBLG) structure is then studied. The analysis of the Raman spectra allows us to directly quantify the effects of doping and of strain on each graphene layer. (C) 2015 Elsevier Ltd. All rights reserved.