Investigation on field emission properties of graphdiyne–BN composite

• We proposed a model to modify electronic structures of the graphdiyne–BN composite.
• We investigated the field emission properties of the graphdiyne–BN composite.
• We detected the binding energy generally increases with the increasing electric field.
• We investigated the propagation mechanisms of nanocracks.
• It implies a potential candidate of field emission devices in the future.

In order to explore the electronic structure and field emission properties of the graphdiyne–BN composite, bond lengths, energy levels, local electron density distributions and Mulliken charges are investigated by first principles method. Our research shows that electronic structures of the graphdiyne–BN composite are modified by the effective movement of Fermi level, and the reduction of band gaps with the increasing electric field, local electron density distributions and conduction of Mulliken charges suggest that field emission properties of this composite are improved significantly. At the same time, we find that the binding energy generally increases with the increasing electric field, which contributes to the stability of the graphdiyne–BN composite. In addition, ionizaton potential decreases linearly with the increasing electric field as well as work functions, which further illustrates the enhancement of field emission properties. Through a series of studies, we believe that the graphdiyne–BN composite may become a potential candidate of field emission devices in the future.