In Situ Study of Graphene Crystallinity Effect on Field Electron Emission Characteristics

Crystallinity and field electron emission characteristics of few-layer graphene (FLG) have been investigated synchronously by using in situ transmission electron microscope (TEM) to reveal their relationship. The crystallinity of a single FLG sheet is modified from polycrystalline to amorphous by TEM electron beam irradiation. In the meantime, the field electron emission measurement shows that the degradation of crystallinity has a negative effect on the field electron emission characteristics. This can be attributed to the violently decline of electrical conductivity of FLG. The results indicate that crystallinity is a key factor to the field electron emission of FLG, and thus, conditions leading to the degradation of crystallinity of FLG should be avoided.