Calcinelli Fabio, Jeindl Andreas, Hörmann Lukas, Ghan Simiam, Oberhofer Harald, Hofmann Oliver T
Institute of Solid State Physics, Graz University of Technology, 8010 Graz, Austria.
Chair for Theoretical Chemistry and Catalysis Research Center, Technical University Munich, 85748 Garching, Germany.
J Phys Chem C Nanomater Interfaces. 2022 Feb 10;126(5):2868-2876. doi: 10.1021/acs.jpcc.1c09986. Epub 2022 Feb 1.
The structure and chemical composition are the key parameters influencing the properties of organic thin films deposited on inorganic substrates. Such films often display structures that substantially differ from the bulk, and the substrate has a relevant influence on their polymorphism. In this work, we illuminate the role of the substrate by studying its influence on -benzoquinone on two different substrates, Ag(111) and graphene. We employ a combination of first-principles calculations and machine learning to identify the energetically most favorable structures on both substrates and study their electronic properties. Our results indicate that for the first layer, similar structures are favorable for both substrates. For the second layer, we find two significantly different structures. Interestingly, graphene favors the one with less, while Ag favors the one with more electronic coupling. We explain this switch in stability as an effect of the different charge transfer on the two substrates.
结构和化学成分是影响沉积在无机衬底上的有机薄膜性能的关键参数。这类薄膜通常呈现出与本体材料有显著差异的结构，并且衬底对其多晶型有重要影响。在这项工作中，我们通过研究衬底对两种不同衬底（Ag(111)和石墨烯）上的对苯醌的影响，阐明了衬底的作用。我们结合第一性原理计算和机器学习来确定两种衬底上能量最有利的结构，并研究它们的电子性质。我们的结果表明，对于第一层，两种衬底都倾向于相似的结构。对于第二层，我们发现了两种明显不同的结构。有趣的是，石墨烯有利于电子耦合较少的结构，而银有利于电子耦合较多的结构。我们将这种稳定性的转变解释为两种衬底上不同电荷转移的结果。
