Electronic structure of phthalocyanine derivative-protected π-junction Au nanoparticles

Abstract

Phthalocyanine derivative-protected Au nanoparticles (H2Pc-AuNPs) can be processed without post-treatment into electroconductive electrodes that exhibit high electrical conductivity. However, the reason for the high electrical conductivity of AuNP films is still unclear. To better understand the carrier transport mechanism in H2Pc-AuNP films, we performed ultraviolet photoelectron spectroscopy, inverse photoelectron spectroscopy and X-ray photoelectron spectroscopy to probe the electronic structure of 2,3,9,10,16,17,23,24-octakis [2-(dimethylamino)ethylthio] phthalocyanine and 2,3,11,12,20,21,29,30-octakis[2-(dimethylamino)ethylthio]naphthalocyanine as ligands for AuNPs. We demonstrated that the ligand molecules are chemisorbed onto AuNP’s surface through formation of Au–S bonds. It can be expected that strong interaction between π-orbitals of the molecules and Au orbitals.