Density Functional Theoretical Study of Perfluoropentacene/Noble Metal Interfaces with van der Waals Corrections: Adsorption States and Vacuum Level Shifts
Density Functional Theoretical Study of Perfluoropentacene/Noble Metal Interfaces with van der Waals Corrections: Adsorption States and Vacuum Level Shifts
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带范德华校正的全氟并五苯/贵金属界面的密度泛函理论研究：吸附状态和真空能级变化
DOI：
10.1021/jp1107262
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发表时间：
2011
影响因子：
3.7
通讯作者：
Y. Morikawa
中科院分区：
文献类型：
--
作者：
K. Toyoda;I. Hamada;Kyuho Lee;S. Yanagisawa;Y. Morikawa
用密度泛函理论和半经验范德华方法(DFT-D)研究了全氟戊二烯(PFP)在铜(111)、银(111)和金(111)上的电子结构。我们发现，密度泛函理论得到了精确的平衡pfp-金属距离，从而使准确预测功函数变化(Δϕ)成为可能。为了研究界面偶极层的性质，我们计算了Δϕ作为PFP-衬底距离的函数，发现与并五苯/金属界面相比，分子扭曲在短距离内对Δϕ有显著的影响。然而，通过从总的功函数变化中减去分子扭曲的贡献，我们发现，在长距离处，功函数的变化不依赖于衬底功函数，而在近距离处，功函数变化与衬底功函数线性变化。我们的结果表明，当PFP分子接近底物时，从肖特基极限到巴丁极限的转变。
We have studied the electronic structures of perfluoropentacene (PFP) on Cu(111), Ag(111), and Au(111) by means of density functional theory with a semiempirical van der Waals method (DFT-D). We show that DFT-D yields accurate equilibrium PFP-metal distances, thereby making an accurate prediction of the work-function change (Δϕ) possible. In order to investigate the nature of the interface dipole layer, we calculated Δϕ as a function of PFP-substrate distance and found that in contrast to pentacene/metal interfaces, the molecular distortion has a significant influence on Δϕ at a short distance. However, by subtracting the contribution of the molecular distortion from the total work-function change, we show that the work-function change does not depend on the substrate work-function at a long distance, while the work-function change varies linearly with the substrate work-function at a short distance. Our results indicate a transition from Schottky to Bardeen limits as a PFP molecule approaches the substra...