摘要

We report first-principles calculations of the energetic stability and electronic properties of metalphthalocyanine (MPc) molecules (M = Cr, Mn, Fe, Co, Ni, Cu, and Zn) adsorbed on the delta-doped Si(111)-B( root 3 x root 3) reconstructed surface. (i) It can be seen that CrPc, MnPc, FePc, and CoPc are chemically anchored to the topmost Si atom. (ii) Contrastingly, the binding of the NiPc, CuPc, and ZnPc molecules to the Si(111)-B(root 3 x root 3) surface is exclusively ruled by van der Waals interactions, the main implication being that these molecules may diffuse and rearrange to form clusters and/or self-organized structures on this surface. The electronic structure calculations reveal that in point (i), owing to the formation of the metal-Si covalent bond, the net magnetic moment of the molecule is quenched by 1 mu(B), remaining unchanged in point (ii). In particular, the magnetic moment of CuPc (1 mu(B)) is preserved after adsorption. Finally, we verify that the formation of ZnPc, CuPc, and NiPc molecular (self-assembled) arrangements on the Si(111)-B(root 3 x root 3) surface is energetically favorable, in good agreement with recent experimental findings.

  • 出版日期2016-3-1