Theoretical investigation of electronic transport in functionalized 2D transition metal dichalcogenides

功能化二维过渡金属二硫属化物中电子传输的理论研究

• 批准号: 280173823
• 负责人: Professor Dr. Thomas Heine
• 金额: --
• 依托单位: Professur für Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/280173823?language=en
• 关键词: Theoretical; investigation; electronic; transport; functionalized

Metallic transition metal dichalcogenide (TMD) monolayers are promising ultrathin materials which have the potential to complete the range of graphene-related materials by offering tunable metallic phases with strong spin-orbit coupling. Many of them can be achieved by small structural deformations and doping of Group 6 TMDs and thus could thus be used as electrode materialswithin a single monolayer, resulting in a very low contact resistance. Experimental study of metallic TMDs is difficult as these phases are often metastable or rely on very subtle structural modifications. Thus, a careful theoretical investigation is imperative before complex experimental studies should be pursued. This consortium will investigate metallic TMD structures, including intrinsically metallic phases, metastable metallic phases, and external factors to trigger semiconductor-metal transitions such as doping, defects and strain. Special attention will be given to spin-orbit splitting and ways to controlthem. Computer simulations will range from band-structure calculations of small unit cells to rather complex systems, including heterostructures, doped and defected systems up to grain boundaries. Conclusions on the suitability of these materials in practical application will be further confirmed byexplicit transport calculations and device simulations. While most calculations can be carried out using state-of-the-art software, some method developments are necessary and will be carried out here. Numerical methods that scale linearly with the system size, O(N), will be developed by using a polynomial expansion of the components of the conductivity tensor. These will allow for simulations of large unit cells in the presence of disorder and the calculation of spin- and valley- dependent contributions. It will become therefore suitable to describe the Spin and Valley Hall effects in realistic models of TMDs.Besides metallic TMDs we will also investigate the possibility of functionalizing semiconducting TMDs for spintronics applications. The possibility of creating the two-dimensional equivalent of the dilute magnetic semiconductor will have a strong impact on spintronics research. By doping with magnetic transition metals, we will investigate the possibility of inducing a tunable magnetic phase transition. On a similar note, we will model the coupling of 2D materials with ferromagnetic contacts and study the effect of disorder and spin-orbit interactions on the performance of such contacts in spintronic devices.The consortium will maintain its excellent relationship to various members of the FLAGSHIP Graphene core project.

金属过渡金属二硫属化物（TMD）单层是有前途的石墨烯材料，其具有通过提供具有强自旋-轨道耦合的可调谐金属相来完成石墨烯相关材料范围的潜力。它们中的许多可以通过小的结构变形和掺杂第6族TMD来实现，因此可以用作单个单层内的电极材料，从而导致非常低的接触电阻。金属TMD的实验研究是困难的，因为这些相通常是亚稳态的或依赖于非常微妙的结构修饰。因此，在进行复杂的实验研究之前，必须进行仔细的理论研究。该联盟将研究金属TMD结构，包括固有的金属相，亚稳金属相，以及引发掺杂，缺陷和应变等金属-金属转变的外部因素。将特别注意自旋轨道分裂和控制它们的方法。计算机模拟的范围从小晶胞的能带结构计算到相当复杂的系统，包括异质结构、掺杂和缺陷系统到晶界。这些材料在实际应用中的适用性的结论将通过显式输运计算和器件模拟得到进一步证实。虽然大多数计算可以使用最先进的软件进行，但一些方法的开发是必要的，将在这里进行。数值方法，规模与系统的大小，O（N），将开发通过使用的电导率张量的分量的多项式展开。这些将允许在无序存在下模拟大的单位晶胞，并计算自旋和谷依赖的贡献。因此，它将成为合适的描述自旋和谷霍尔效应在现实模型的TMDs。除了金属的TMDs，我们还将研究功能化半导体TMDs的自旋电子学应用的可能性。创造二维等效稀磁半导体的可能性将对自旋电子学的研究产生强烈的影响。通过掺杂磁性过渡金属，我们将研究诱导可调磁性相变的可能性。此外，我们还将对二维材料与铁磁接触的耦合进行建模，并研究无序和自旋轨道相互作用对自旋电子器件中此类接触性能的影响。该联盟将与FLAGSHIP石墨烯核心项目的各个成员保持良好的关系。