2D graphdiyne: an excellent ultraviolet nonlinear absorption material.

With an sp2-hybridized carbon atom structure, graphene is recognized as a nonlinear absorption (NLA) material, which has motivated scientists to explore new allotropes of carbon. Different from graphene, graphdiyne (GDY) consists of sp- and sp2-hybridized carbon atoms. An sp-hybridized carbon-carbon triple bond structure will bring in novel nonlinear optical properties, which are different from other allotropes of carbon.