Doped Aromatic Thin Films with Superconducting Capabilities

具有超导能力的掺杂芳香族薄膜

• 批准号: 266990799
• 负责人: Dr. Roman Forker
• 金额: --
• 依托单位: Lehrstuhl für Angewandte Physik / Festkörperphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/266990799?language=en
• 关键词: Doped; Aromatic; Thin; Films; Superconducting

Polycyclic aromatic hydrocarbons (PAHs) recently emerged as a new class of superconducting materials upon doping by metal atom intercalation; with critical temperatures already higher than 30 K. Key factors for the superconductivity in the organic compounds are the appropriate ratio of dopant atoms per organic molecule as well as the interplay between the doping and the crystal structure formed. In this research project we aim at a deeper understanding of the influence of doping by alkali and earth alkali metals on the physical properties (i.e., structural, optical, and electronic properties) of several PAHs - with either potential or already documented superconductivity - in thin films, as opposed to powder samples used in most previous studies. By covering the thickness range from (epitaxial) monolayers up to films several nanometers thick and applying selected spectroscopic methods, namely optical differential reflectance spectroscopy (DRS) and scanning tunneling spectroscopy (STS) in a temperature range from 300 K down to 1 K, we shall obtain comprehensive and complementary data to characterize the influence of the applied doping on the electronic and optical properties. Those measurements will be accompanied by thorough structural characterization (MCP-LEED, ST[H]M, AFM), in order to obtain information on the influence of the doping on the crystallographic structure and to elucidate the docking sites of the doping atoms on the molecules in doped mono- and multilayers. In particular scanning tunneling hydrogen microscopy (STHM) shall be employed, which has already been successfully applied in our group for the precise location of individual potassium dopants within a molecular layer. The ultimate goal is to unequivocally demonstrate the superconducting states by determining the corresponding energy gap via STS and to establish general rules identifying which PAHs are successful candidates for organic superconductors. Our working hypothesis is that the presence of degenerate molecular levels may play a major role. To elucidate this, we will include different PAHs in our research, some of those possessing degenerate frontier orbitals, others not.

多环芳烃（PAH）最近通过金属原子插层掺杂成为一类新型超导材料；临界温度已经高于 30 K。有机化合物超导性的关键因素是每个有机分子中掺杂剂原子的适当比例以及掺杂与形成的晶体结构之间的相互作用。在这个研究项目中，我们的目标是更深入地了解碱金属和碱土金属的掺杂对薄膜中几种多环芳烃的物理性质（即结构、光学和电子性质）的影响，这些多环芳烃具有潜在的或已经记录的超导性，而不是大多数先前研究中使用的粉末样品。通过覆盖从（外延）单层到几纳米厚的薄膜的厚度范围，并在 300 K 至 1 K 的温度范围内应用选定的光谱方法，即光学差示反射光谱 (DRS) 和扫描隧道光谱 (STS)，我们将获得全面和补充的数据来表征所应用的掺杂对电子和光学性能的影响。这些测量将伴随彻底的结构表征（MCP-LEED、ST[H]M、AFM），以获得掺杂对晶体结构影响的信息，并阐明掺杂单层和多层分子上掺杂原子的对接位点。特别是应采用扫描隧道氢显微镜（STHM），该技术已在我们小组中成功应用于分子层内单个钾掺杂剂的精确定位。最终目标是通过 STS 确定相应的能隙，明确展示超导态，并建立确定哪些 PAH 是有机超导体的成功候选者的一般规则。我们的工作假设是简并分子水平的存在可能发挥重要作用。为了阐明这一点，我们将在我们的研究中纳入不同的多环芳烃，其中一些具有简并前沿轨道，另一些则没有。

项目成果

In-depth characterization of annealing-induced restructuring processes of doped organic adlayers

掺杂有机吸附层退火诱导重组过程的深入表征

• DOI: 10.1103/physrevmaterials.3.085604
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: C. Zwick;M. Meissner;F. Sojka;R. Forker;T. Fritz
• 通讯作者: T. Fritz

Insight into the unit cell: Structure of picene thin films on Ag(100) revealed with complementary methods.

• DOI: 10.1063/1.4966200
• 发表时间: 2016-11
• 期刊: The Journal of chemical physics
• 作者: Tobias Huempfner;Martin Hafermann;Christian Udhardt;F. Otto;R. Forker;T. Fritz

Ordered Growth and Electronic Properties of 1,2:8,9-Dibenzopentacene (trans-DBPen) on Ag(111)

Ag(111) 上 1,2:8,9-二苯并五苯 (trans-DBPen) 的有序生长和电子性质

• DOI: 10.1021/acs.jpcc.8b00095
• 发表时间: 2018
• 期刊: Journal of Physical Chemistry C
• 影响因子: 3.7
• 作者: F. Otto;T. Huempfner;M. Schaal;C. Udhardt;L. Vorbrink;B. Schroeter;R. Forker;T. Fritz
• 通讯作者: T. Fritz