Interface dipole formation of different ZnPcCl8 phases on Ag(111) observed by Kelvin probe force microscopy
Interface dipole formation of different ZnPcCl8 phases on Ag(111) observed by Kelvin probe force microscopy
复制标题
开尔文探针力显微镜观察Ag(111)上不同ZnPcCl8相的界面偶极子形成
作者：
P. Milde;U. Zerweck;Lukas M. Eng;Mathieu Abel;L. Giovanelli;L. Nony;M. Mossoyan;Louis Porte;C. Loppacher
最近，我们用扫描隧道显微镜研究了八氯酞菁锌（ZnPcCl_8）在Ag（111）表面的吸附。与标准酞菁相比，卤代酞菁分子表现出更为复杂的键合行为，形成了三种不同的结构相。这些相来自有序化过程，形成8、4和0个分子间氢-卤素键（Abel等人，2006 ChemPhysChem 7 82）。在目前的工作中，我们调查这些阶段的开尔文探针力显微镜，以定量推导的第一单层的电界面势垒。我们的测量结果表明，结合行为不仅会影响结构的有序性，而且会影响界面偶极子的形成，从而导致不同的功函数。我们观察到有序和无序分子层之间符号相反的界面势垒的事实强调了组装有机分子器件时准确了解界面处分子排列的重要性。
Recently, we investigated the adsorption of octachloro zinc phthalocyanine (ZnPcCl8) on Ag(111) by scanning tunneling microscopy. Compared to the standard phthalocyanine, halogenated phthalocyanine molecules show a much more complex binding behavior, which results in the formation of three different structural phases. These phases follow from the ordering process with the formation of 8, 4 and 0 intermolecular hydrogen–halogen bonds (Abel et al 2006 ChemPhysChem 7 82). In the present work we investigate these phases by Kelvin probe force microscopy in order to quantitatively deduce the electric interface barrier of the first monolayer. Our measurements reveal that the binding behavior does not only affect the structural ordering but also the interface dipole formation, which leads to different work functions. The fact that we observe interface barriers of opposite signs between ordered and disordered molecular layers underlines the importance of exactly knowing the molecular arrangement at the interface when assembling organic molecule devices.