Improvement of sensitivity of graphene photodetector by creating bandgap structure
Zhang Ni-Zhen1, He Meng-Ke1, Yu Peng1, †, Zhou Da-Hua2, ‡
       

(color online) (a) Early stages of graphene grown on the Cu foil. (b) SEM image of the surface morphology of transferred graphene onto SiO2 after removing PMMA by acetone.