Fully Atomistic Understanding of the Electronic and Optical Properties of a Prototypical Doped Charge-Transfer Interface.
Fully Atomistic Understanding of the Electronic and Optical Properties of a Prototypical Doped Charge-Transfer Interface.
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DOI：
10.1021/acsnano.7b05828
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发表时间：
2017-10-24
期刊：
影响因子：
17.1
通讯作者：
Zojer E
中科院分区：
文献类型：
--
作者：
Baby A;Gruenewald M;Zwick C;Otto F;Forker R;van Straaten G;Franke M;Stadtmüller B;Kumpf C;Brivio GP;Fratesi G;Fritz T;Zojer E
目前的研究对掺杂引起的典型PTCDA/Ag（111）界面的光学和电子性质的变化产生了深刻的原子性见解。由于KxPTCDA/Ag（111）具有形成定义良好的化学计量相的明显优势，因此使用K原子进行掺杂。为了获得对界面特性的结论性、明确性和完全原子性的理解，我们将最先进的密度泛函理论计算与光学微分反射率数据、光电子能谱和x射线驻波测量相结合。结合低能电子衍射和扫描隧道显微镜实验对KxPTCDA/Ag（111）界面的完整结构表征（ACS Nano2016, 10, 2365-2374），本综合研究为掺杂原子存在下定义良好的金属-有机界面提供了一个完全表征的参考体系，可以作为未来研究和应用的理想基准。所采用的互补技术的结合使我们能够理解K2PTCDA/Ag（111）的光谱特性及其与中性PTCDA层的反直觉相似性。他们还清楚地描述了从（原始）吸附在Ag（111）上的PTCDA层的金属特征到掺杂后半导体状态的转变，这与（简并）掺杂通常对半导体材料的影响相反。所有的实验和理论努力也一致表明，吸附物和底物之间的电子耦合减少了，这与PTCDA分子的吸附距离增加有关，这是由它们的羧基氧从底物向钾原子弯曲引起的。
The current study generates profound atomistic insights into doping-induced changes of the optical and electronic properties of the prototypical PTCDA/Ag(111) interface. For doping K atoms are used, as KxPTCDA/Ag(111) has the distinct advantage of forming well-defined stoichiometric phases. To arrive at a conclusive, unambiguous, and fully atomistic understanding of the interface properties, we combine state-of-the-art density-functional theory calculations with optical differential reflectance data, photoelectron spectra, and X-ray standing wave measurements. In combination with the full structural characterization of the KxPTCDA/Ag(111) interface by low-energy electron diffraction and scanning tunneling microscopy experiments (ACS Nano2016, 10, 2365–2374), the present comprehensive study provides access to a fully characterized reference system for a well-defined metal–organic interface in the presence of dopant atoms, which can serve as an ideal benchmark for future research and applications. The combination of the employed complementary techniques allows us to understand the peculiarities of the optical spectra of K2PTCDA/Ag(111) and their counterintuitive similarity to those of neutral PTCDA layers. They also clearly describe the transition from a metallic character of the (pristine) adsorbed PTCDA layer on Ag(111) to a semiconducting state upon doping, which is the opposite of the effect (degenerate) doping usually has on semiconducting materials. All experimental and theoretical efforts also unanimously reveal a reduced electronic coupling between the adsorbate and the substrate, which goes hand in hand with an increasing adsorption distance of the PTCDA molecules caused by a bending of their carboxylic oxygens away from the substrate and toward the potassium atoms.
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影响因子：
3.7
作者：
Egger, David A.;Ruiz, Victor G.;Said, Wissam A.;Bucko, Tomas;Tkatchenko, Alexandre;Zojer, Egbert
通讯作者：
Zojer, Egbert
影响因子：
10.8
作者：
Froudakis, GE
通讯作者：
Froudakis, GE
影响因子：
18.3
作者：
HADDON, RC
通讯作者：
HADDON, RC
影响因子：
64.8
作者：
HEBARD, AF;ROSSEINSKY, MJ;KORTAN, AR
通讯作者：
KORTAN, AR
影响因子：
3.2
作者：
Duhm, S.;Gerlach, A.;Koch, N.
通讯作者：
Koch, N.