Importance of heteroatom doping site in tuning the electronic structure and magnetic properties of graphdiyne

Density functional theory calculations are carried out to study the electronic structures and magnetic properties of single X (X = B, N, 0, P, S) atom doped graphdiyne (GDY) monolayers. It is found that there are three distinct doped models (one benzene ring site X-b, two acetylene linkage sites X-1, X-2), and the heteroatom (B, N, 0, P, S) doping site has a serious effect on the electronic structure and magnetic properties of GDYs. The results of cohesive energies reveal that the B and S atoms prefer to substitute the sp(2) -hybridized C atom at benzene ring, while N, O, P atoms prefer to substitute the sp-hybridized C atom at acetylene linkage. For B, N, O, S-doped GDYs exhibit metallic character, while P-1, P-2 doped GDYs present semiconductor character. The X-1, X-2 (X = B, O, P, S) GDYs with heteroatom at chain site introduce spin polarization, and are magnetic, whereas the X-b (X = B, O, P, S) doped GDYs are nonmagnetic. The N doping site has no impact on its magnetic properties, and all the N doped GDYs are nonmagnetic. The research results offer a theoretical support that heteroatom doping plays an important role in tuning the electronic structures and magnetic properties of GDYs.