Theoretical and Experimental Study of Metal-phthalocyanines on Ag(111).
2009 (English)Conference paper, Poster (Refereed)
Metal-phthalocyanines deposited and/or self-assembled on metal surface are considered as candidates for novel molecular sensors; molecular memories and photovoltaic cells. To study the adsorption of three metal-phthalocyanines (MPc (M=Co; Sn; Pb) on Ag(111) we performed density functional theory DFT calculations using the generalized gradient approximation (GGA) parameterization by Pedrew-Burke-Ernzerhof (PBE) for the exchange-correlation energy [1;2]. Three initial adsorption site were considered (hcp-hollow; fcc-hollow and on-top). Our results show that the most favourite adsorption site is hcp-hollow for SnPc and PbPc and on-top for CoPc. All calculated structures are compared with experimental data obtained by normal incidence X-ray standing wave spectroscopy (NIXSW) [3;4] Good agreement in binding geometries with experiment was found. To understand the hybridization of MPc s molecular orbitals with silver orbitals we have compared selected partial density of states PDOS for a free and adsorbed MPcs. SnPc and PbPc hybridize mostly with surface by central metal atom; however the effect from the aromatic rings is not negligible. Adsorption of CoPc on the silver surface results in a transfer of electron density from the surface to the central Co atom. After adsorption; the magnetic moment of CoPc is completely quenched which is in agreement with similar studies on adsorption on Au(111) . Binding energies for all of systems are reported showing chemisorptive nature of the molecule-metal surface interaction
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IdentifiersURN: urn:nbn:se:ltu:diva-34986Local ID: 952a358c-545c-4a83-879b-fe5256ba3265OAI: oai:DiVA.org:ltu-34986DiVA: diva2:1008238
Nanoscale Simulators in Ireland. Meeting : 15/12/2008 - 16/12/2008
Upprättat; 2009; 20130412 (andbra)2016-09-302016-09-30