论文标题
Si（100）表面上的二维官能化超薄半绝缘CAF2层在低温下用于分子电子解耦AH-2083 ARXIV提交/3480305
Two Dimensional Functionalized Ultrathin Semi Insulating CaF2 Layer on the Si(100) Surface at a Low Temperature for Molecular Electronic Decoupling AH-2083 arXiv submit/3480305
论文作者
论文摘要
精确控制从表面吸附物的电子耦合/解耦的能力是一个基本目标。对于表面科学中的基础研究，而且在几个应用领域中，包括微型分子电子或开发各种设备的纳米级生物传感器或光伏细胞的开发。在这里，我们通过CAF2的外延在硅表面上生长的半胰腺表面上的半胰腺测定剂进行了原子级实验和理论研究。在润湿层的形成之后，我们彰显了随后的有组织的单元格与周期性地位于周围环境中的其他物理学的CAF2Molecules耦合。这种构型的饰物形成了使半导体表面功能化的条带的丝带。所获得的组件具有单层键，揭示了3.2 eV的表面间隙能。通过差分电导测量值，使用了条纹丝带上铁四苯基孢子蛋白分子的吸附。密度功能理论（DFT）包括几个级别的复杂性（退火，DFT +U和非局部范德华功能）来重现我们的实验观察结果。我们的发现提供了一个独特且坚固的模板，为金属表面上的NACL带来了电子半绝制层的替代解决方案。因此，长度可以达到100 nm的条纹结构的CAF2/Si（100）带作为分子设备各种原子级研究的厌恶表面平台。
The ability to precisely control the electronic coupling/decoupling of adsorbates from surfaces is an essential goal. It isimportant for fundamental studies not only in surface science but alsoin several applied domains including, for example, miniaturizedmolecular electronic or for the development of various devices suchas nanoscale biosensors or photovoltaic cells. Here, we provide atomic-scale experimental and theoretical investigations of a semi-insulatinglayer grown on a silicon surface via its epitaxy with CaF2. We showthat, following the formation of a wetting layer, the ensuing organizedunit cells are coupled to additional physisorbed CaF2molecules,periodically located in their surroundings. This configuration shapesthe formation of ribbons of stripes that functionalize the semi-conductor surface. The obtained assembly, having a monolayerthickness, reveals a surface gap energy of 3.2 eV. The adsorption of iron tetraphenylporphyrin molecules on the ribbons of stripes is used to estimate the electronic insulating properties of thisstructure via differential conductance measurements. Density functional theory (DFT) including several levels of complexity(annealing, DFT +U, and nonlocal van der Waals functionals) is employed to reproduce our experimental observations. Ourfindings offer a unique and robust template that brings an alternative solution to electronic semi-insulating layers on metal surfacessuch as NaCl. Hence, CaF2/Si(100) ribbon of stripe structures, whose lengths can reach more than 100 nm, can be used as aversatile surface platform for various atomic-scale studies of molecular devices.
