▎ 摘　　要

Quantum mechanical-based kinetic Monte-Carlo calculations (KMC) are used to investigate mechanisms of degradation of graphene devices subjected to 10-keV x-ray irradiation, ozone exposure, and subsequent high-temperature annealing. Using KMC, we monitor the time evolution of defect concentrations on a graphene surface. The degradation mechanism for oxygen exposure and subsequent anneal of graphene surface greatly depends on the temperature and initial concentrations of H and O atoms on the graphene surface. At oxygen surface coverage of similar to 0.05 and higher, the damage is caused by formation of vacancies due to desorption of CO and CO2. Hydrogen facilitates the removal of O without introducing vacancies.