期刊
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
卷 -, 期 -, 页码 -出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/anie.202314663
关键词
Density functional calculations; Monolayers; N-heterocyclic olefins; Scanning tunneling microscopy; Silicon
In this study, we investigated the adsorption properties of N-heterocyclic olefins (NHOs) on silicon and found that the adsorption geometry strongly depends on the N-substituents. Different N-substituents result in different adsorption geometries, with larger N-substituents favoring upright adsorption and smaller N-substituents favoring flat-lying geometry. These different geometries have a significant impact on the properties of the obtained monolayers, such as their work function.
The adsorption of N-heterocyclic olefins (NHOs) on silicon is investigated in a combined scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory study. We find that both of the studied NHOs bind covalently, with ylidic character, to the silicon adatoms of the substrate and exhibit good thermal stability. The adsorption geometry strongly depends on the N-substituents: for large N-substituents, an upright adsorption geometry is favored, while a flat-lying geometry is found for the NHO with smaller wingtips. These different geometries strongly influence the quality and properties of the obtained monolayers. The upright geometry leads to the formation of ordered monolayers, whereas the flat-lying NHOs yield a mostly disordered, but denser, monolayer. The obtained monolayers both show large work function reductions, as the higher density of the flat-lying monolayer is found to compensate for the smaller vertical dipole moments. Our findings offer new prospects in the design of tailor-made ligand structures in organic electronics and optoelectronics, catalysis, and material science. The binding of N-heterocyclic olefins to a silicon surface is investigated revealing an adsorption in the ylide form drastically depending on the N-substituents. Large N-substituents lead to upright molecules and ordered monolayers while for small N-substituents a flat-lying geometry is favored. The geometry is found to have a strong influence on the properties of the films, e.g. their work function.+image
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据