Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)
Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)
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DOI：
10.3762/bjnano.11.101
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发表时间：
2020-08
影响因子：
3.1
通讯作者：
M. Schaal;Takumi Aihara;M. Gruenewald;F. Otto;J. Domke;R. Forker;H. Yoshida;T. Fritz
中科院分区：
文献类型：
--
作者：
M. Schaal;Takumi Aihara;M. Gruenewald;F. Otto;J. Domke;R. Forker;H. Yoshida;T. Fritz
二维材料如六方氮化硼（h-BN）被广泛用于将有机分子与金属衬底解耦。然而，在文献中也有明显的杂交迹象，这导致了固有分子性质的扰动。在这项工作中，我们研究了四苯基二benzoperiflanthene （DBP）在Ni（111）上有和没有原子薄的h-BN间层的电子和光学性质以及横向结构，以研究其可能的解耦效应。为此，我们使用原位差分反射光谱作为一种既定的方法来区分杂交分子和解耦分子。通过插入h-BN中间层，我们制造了一个埋藏界面，并表明DBP分子与Ni（111）表面很好地解耦。此外，在170°C的底物温度下沉积分子，在h-BN/Ni（111）上获得了高度有序的DBP单层。通过定量低能电子衍射和低温扫描隧道显微分析得到了结构结果。最后，利用紫外光电子能谱对h-BN/Ni（111）的价带结构进行了研究，发现DBP沉积后h-BN/Ni（111）的低功函数进一步降低。因此，h- bn钝化的Ni（111）表面可以作为未来分子电子器件的潜在n型接触面。
2D materials such as hexagonal boron nitride (h-BN) are widely used to decouple organic molecules from metal substrates. Nevertheless, there are also indications in the literature for a significant hybridization, which results in a perturbation of the intrinsic molecular properties. In this work we study the electronic and optical properties as well as the lateral structure of tetraphenyldibenzoperiflanthene (DBP) on Ni(111) with and without an atomically thin h-BN interlayer to investigate its possible decoupling effect. To this end, we use in situ differential reflectance spectroscopy as an established method to distinguish between hybridized and decoupled molecules. By inserting an h-BN interlayer we fabricate a buried interface and show that the DBP molecules are well decoupled from the Ni(111) surface. Furthermore, a highly ordered DBP monolayer is obtained on h-BN/Ni(111) by depositing the molecules at a substrate temperature of 170 °C. The structural results are obtained by quantitative low-energy electron diffraction and low-temperature scanning tunneling microscopy. Finally, the investigation of the valence band structure by ultraviolet photoelectron spectroscopy shows that the low work function of h-BN/Ni(111) further decreases after the DBP deposition. For this reason, the h-BN-passivated Ni(111) surface may serve as potential n-type contact for future molecular electronic devices.