▎ 摘　　要

Thermal annealing of graphene was studied to improve the thermal stability. During the annealing under an Ar atmosphere with temperature from 100 degrees C to 600 degrees C, graphene exhibits partial removal of PMMA residues, low density of defect cracks in SEM images and relatively low I-D/I-G ratios in Raman spectrum probing. For a top-gated graphene transistor with thermal annealing, it performs high carrier mobility up to 3500 cm(2) V-1 s(-1) and slightly asymmetric bipolar behaviours as well as slight Dirac point variation within +/- 0.2 V. (C) 2016 Elsevier Ltd. All rights reserved.