▎ 摘　　要

The aim of this paper is to implement a theoretical prediction and evaluation on the quality of graphene-C-70 composite as cathode material. The pristine graphene-C-70 composite and the B-doped graphene-C-70 composites were constructed to investigate their field emission properties. The results suggest that the work function (WF) and ionization potential (IP) of the composites decrease with the increasing electric field. It implies that the electron emission becomes. more and more easy. Under the field, the molecular orbital energy levels close to the vacuum level and their energy gap also has a declining trend. It means a good trend for improving the field emission properties of the composites. The above mentioned results show that the composites have the advanced capacity for electron emission and the potential for cathode material. It makes us believe that the composites will be the good field emission electron sources in the electronic device fabrication and the investigation can give a theoretical guidance for the corresponding experiments and may develop the application of fullerene for field emission. (C) 2017 Elsevier B.V. All rights reserved.