Beryllium and boron decoration forms planar tetracoordinate carbon strips at the edge of graphene nanoribbons.

Graphene has been viewed as one of the most promising materials in many fields. Recently, it has been found that by using Cu-decoration at the edge of zigzag graphene nanoribbons (ZGNR), a novel kind of planar tetracoordinate carbon (ptC) strip can be formed. In this paper, we investigate the edge-decoration of armchair graphene nanoribbons (AGNR) by various atom types and find that two new kinds of ptC strip can be effectively formed by using Be or B decoration. For the Be-decorated AGNR, the edge Be atoms take the form of a "zigzag-like" chain, and all the edge C atoms have a ptC nature. However, for the B-decorated AGNR, the edge B atoms form an infinite yet "fractured" chain consisting of separate B(4)-subunits, which results in only 50% of the edge C atoms being ptCs, in contrast with Be-decorated AGNR and Cu-decorated ZGNR. The high thermal stability of both types of ptC-based AGNR is indicated by isomeric sampling and molecular dynamics simulations.