Straintronics of imperfect quasi-two-dimensional materials: coplanar vs lamellar heterostructures

在过去的几年里，越来越多的二维(2D)材料(除了石墨烯之外)的发现导致了一个新的实验和理论研究方向，其目标是开发这些2D系统迷人的电子、结构和输运性质。显然，获得对这些性质的控制是将2D材料用于纳米电子学、热学或自旋电子学应用的先决条件。特别是，纳米电子应用需要了解各种长度尺度上的电荷传输特性，以及各种外在(电场、磁场、光场等)对电子传输的影响。或本征(局部和扩展缺陷、表面功能化等)变量。在目前的提案中，我们结合了两个相关研究小组在纳米系统中电荷传输建模方面的深厚专业知识，以解决选定的共面和层状异质结构中的应变和缺陷工程问题。为了在拟议的资金期内保持明确的重点，我们将仅限于石墨烯和磷烯异质结构，尽管显然其他可能性可能会引起兴趣。我们结合了几纳米尺度的原子量子输运方法(德国德累斯顿工业大学)和数百纳米尺度的真实空间Kubo方法(乌克兰国家科学院)，以阐明如何使用各种类型的缺陷(主要是空位、杂质和晶界)和施加的应变(包括均匀和非均匀的)来调节石墨烯/磷烯异质结构中的电荷传输。两个小组之间的主要联系将包括：(I)根据德国合作伙伴进行的原子计算，对乌克兰合作伙伴将使用的有效模型进行广泛的参数化，(Ii)(由德国方面)确定层内和层之间可能的亚稳定缺陷配置，以便(由乌克兰方面)随后计算其对电子扩散率和电子传导性的影响，以及(Iii)计算机辅助设计具有独特原子配置和具有潜在应用于纳米电子学、磁电子学、传感器学、我们预计，该项目所取得的成果不仅对双方都有意义，而且能够引发乌克兰国家科学院金属物理研究所和基辅塔拉斯·舍甫琴科国立大学固体物理物理研究所电子结构和电子性质系在二维材料和异质结构领域的适当实验调查。

Over the past few years, the discovery of an increasingly large number of two-dimensional (2D) materials (besides graphene) has led to the emergence of a new experimental and theoretical research direction, whose goal is the exploitation of the fascinating electronic, structural, and transport properties of these 2D systems. Gaining control over those properties is clearly a pre-condition for the use of 2D materials in nanoelectronics, thermal or spintronics applications. In particular, nanoelectronic applications require the understanding of charge transport properties over various length scales as well as how electrical transport can be influenced by various extrinsic (electric, magnetic, light fields, etc.) or intrinsic (local and extended defects, surface functionalization, etc.) variables. In the current proposal, we combine the deep expertise of the two involved research groups in the modelling of charge transport in nanoscale systems to address the problem of strain and defect engineering in selected co-planar and lamellar heterostructures. For the sake of keeping a clear focus over the proposed funding period, we will limit ourselves to graphene and phosphorene heterostructures, although clearly other possibilities may be of interest. We combine atomistic quantum-transport approaches (TU Dresden, Germany) at the few-nanometers scale with real-space Kubo approaches (National Academy of Science, Ukraine) at a few hundreds of nanometers scale to elucidate the problem of how various types of defects (mostly vacancies, impurities, and grain boundaries) and (both homogeneously and inhomogeneously) applied strains can be used to tune charge transport in graphene/phosphorene heterostructures. The main links between both groups will consist in (i) the extensive parametrization of effective models to be used by the Ukrainian partner on the basis of the atomistic calculations to be performed by the German partner, (ii) the determination of possible meta-stable defect configurations within and in between the layers (by the German side) for subsequent calculations (by the Ukrainian side) of their effect on the electron diffusivity and electronic conductivity, and (iii) computer-aided design of nanoscale heterostructures with unique atomic configurations and shapeable (stretchable and flexible) structures with a potential for applications in nanoelectronics, magnetoelectronics, sensorics, etc. We expect that the results obtained within this project will not only have significance from the point of view of knowledge gain for both partners, but also be able to trigger appropriate experimental investigations in the field of straintronics of 2D materials and heterostructures in both the Department of Electronic Structure and Electronic Properties at the G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine and the Research Laboratory of Physical Materials Science of a Solid at the Taras Shevchenko National University of Kyiv.