Effect of electrostatic screening on apparent shifts in photoemission spectra near metal/organic interfaces
Effect of electrostatic screening on apparent shifts in photoemission spectra near metal/organic interfaces
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DOI：
10.1103/physrevb.81.153308
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发表时间：
2010-04-15
影响因子：
3.7
通讯作者：
Lu, Z. H.
中科院分区：
文献类型：
--
作者：
Helander, M. G.;Greiner, M. T.;Lu, Z. H.
很薄的有机薄膜的光电发射光谱不同于较厚的块状薄膜。特别地，在金属/有机界面处的分子轨道中的结合能位移作为有机覆盖层厚度的函数而变化。使用一个简单的图像电荷模型，它被发现，静电屏蔽可以有显着的效果上的最终状态弛豫能。各种介质基板的实验结果和理论计算之间的良好协议表明，报告的厚度依赖的有机覆盖层光谱的能级位移可以占静电屏蔽。因此，基于有机薄膜光电子能谱的有机界面模型应该重新研究。
Photoemission spectra of very thin organic films differ from that of thicker bulklike films. In particular, the binding-energy shifts in molecular orbitals at metal/organic interfaces vary as a function of the organic over-layer thickness. Using a simple image-charge model it is found that electrostatic screening can have a significant effect on the final-state relaxation energy. Good agreement between experimental results and theoretical calculations for a variety of dielectric substrates indicate that reported thickness dependent energy-level shifts in organic overlayer spectra can be accounted for by electrostatic screening. Models of organic interfaces based on photoemission spectra of organic thin films should therefore be re-examined.