The effect of electrical properties of graphene transistors by heating in vacuum and atmosphere

In this paper, a comparison experiment is reported. After a graphene field effect transistor is heated in a 120 Celsius vacuum for 4 hours, its Dirac point voltage decreases 12V and maximum absolute transconductance increases 10.6 microsiemens. However, while an identical graphene field effect transistor is heated in atmosphere with the same temperature and time span, the case is on the contrary that the Dirac point voltage increases 19V and maximum absolute transconductance decreases 4.4 microsiemens. These results suggest that heating in vacuum is benefit to reduce P type impurities and enhance the mobility of graphene, but heating in atmosphere is opposite.