Hörmann Lukas, Jeindl Andreas, Hofmann Oliver T
Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
Nanoscale. 2022 Mar 31;14(13):5154-5162. doi: 10.1039/d1nr07763e.
Virtually all organic (opto)electronic devices rely on organic/inorganic interfaces with specific properties. These properties are, in turn, inextricably linked to the interface structure. Therefore, a change in structure can introduce a shift in function. If this change is reversible, it would allow constructing a switchable interface. We accomplish this with tetrachloropyrazine on Pt(111), which exhibits a double-well potential with a chemisorbed and a physisorbed minimum. These minima have significantly different adsorption geometries allowing the formation of switchable interface structures. Importantly, these structures facilitate different work function changes and coherent fractions (as would be obtained from X-ray standing wave measurements), which are ideal properties to read out the interface state. We perform surface structure search using a modified version of the SAMPLE approach and account for thermodynamic conditions using thermodynamics. This allows investigating millions of commensurate as well as higher-order commensurate interface structures. We identify three different classes of structures exhibiting different work function changes and coherent fractions. Using temperature and pressure as handles, we demonstrate the possibility of reversible switching between those different classes, creating a dynamic interface for potential applications in organic electronics.
几乎所有的有机（光）电子器件都依赖于具有特定性质的有机/无机界面。这些性质又与界面结构紧密相连。因此，结构的变化会导致功能的转变。如果这种变化是可逆的，就可以构建一个可切换的界面。我们在Pt(111)上用四氯吡嗪实现了这一点，它表现出一个具有化学吸附和物理吸附最小值的双阱势。这些最小值具有显著不同的吸附几何结构，从而允许形成可切换的界面结构。重要的是，这些结构促进了不同的功函数变化和相干分数（如通过X射线驻波测量所获得的），这是读出界面状态的理想性质。我们使用SAMPLE方法的改进版本进行表面结构搜索，并利用热力学考虑热力学条件。这使得我们能够研究数百万种共格以及高阶共格的界面结构。我们识别出三类具有不同功函数变化和相干分数的结构。通过将温度和压力作为控制变量，我们展示了在这些不同类别之间进行可逆切换的可能性，从而为有机电子学中的潜在应用创建了一个动态界面。
