Supramolecular Approaches to Novel Physical scenarios in Hybrid van der Waals Heterostructures and Organic Semiconductors

我的研究项目调查了器件中分子和二维材料的电荷和自旋输运，特别关注异质界面的超分子控制所产生的影响，即金属/半导体、电介质/半导体或二维共价键（半导体）导体上的分子非共价晶格等界面。界面是我研究计划中的一个关键因素，因为它们直接影响(i)电导率，（ii）局部带形状，（iii）电荷和自旋输运（iv）光学性质，最终(v)本研究计划将重点关注的材料类别中的器件物理。控制这样的接口可以产生新颖和令人兴奋的物理场景。我的研究项目主要集中在：(1)由二维超分子晶格（SLs）在二维材料（如石墨烯或过渡金属二硫化物（TMDCs））上形成的杂化范德华异质结构。与最近提出的由多层共价键结合的二维材料通过弱相互作用形成的范德华异质结构相反，在我的研究计划中，我将探索由石墨烯或TMDCs上的二维SLs形成的混合系统中出现的新物理场景。特别令人感兴趣的是SLs在石墨烯和TMDCs上产生周期电位的影响，因为这种周期电位可以通过分子设计预先编程并以原子精度控制。裁剪这种周期势是一种新颖的方法，也是目前二维材料物理学中的一个热门话题。此外，将通过低温和高磁场下的电表征研究含重原子分子的SLs对石墨烯介观特性的影响，探索叠加SLs对石墨烯和TMDCs的量子指纹图谱（如量子霍尔、Shubnikov-de Haas振荡和弱（反）局域化）的影响。(2)通过研究不同的分子体系和超分子结构，了解和控制超分子组装有机半导体中的自旋混合规律和磁电阻。特别是，我们将专注于理解双极极子形成机制，分子设计和超分子结构之间的关系，同时测量通过层层垂直结构实现的聚合物薄膜中的磁电阻，其中系统维度从2D（单层）到3D（多层薄膜）的影响将在低温（低至4 K）和高磁场（高达7 T）下探索。此外，我们还将研究准一维半导体线中链内和链间跳速的作用，以及它对超分子结构中诱导自旋阻滞的相关影响。

My research program investigates charge and spin transport of both molecular and 2D materials in devices with special focus on the effects arising from the supramolecular control of hetero-interfaces i.e. interfaces such as metal/semiconductor, dielectric/semiconductor or molecular non-covalent lattices over 2D covalently bonded (semi)conductors. Interfaces are a key element in my research program because they impact directly (i) conductivity, (ii) local band shape, (iii) charge and spin transport (iv) optical properties and, ultimately the (v) device physics in the class of materials this research program will be focusing on. Controlling such interfaces can give rise to novel and exciting physical scenarios. My research program focuses on: (1) Hybrid van der Waals heterostructures formed by 2D supramolecular lattices (SLs) over 2D materials such as graphene or transition metals dichalcogenides (TMDCs). In contrast with the recently suggested van der Waals heterostructures formed by multilayers of covalently-bonded 2D materials held together by weak interactions, within my research program I will explore new physical scenarios arising in hybrid systems formed by two-dimensional SLs over graphene or TMDCs. Of particular interest will be the effect of SLs in generating periodic potentials over graphene and TMDCs because such periodic potentials can be pre-programmed by molecular design and controlled with atomic precision. Tailoring such periodic potentials is novel and is currently a hot topic in 2D materials Physics. Furthermore, SLs containing molecules bearing heavy atoms affecting the mesoscopic characteristics of graphene will be studied by electrical characterization at low temperature and high magnetic fields, to explore the effects of superimposed SLs on quantum fingerprints of graphene and TMDCs such as Quantum Hall, Shubnikov-de Haas oscillations and weak (anti)localization. (2) Understanding and controlling the spin-mixing rules and magnetoresistance in supramolecularly assembled organic semiconductors by studying different molecular systems and supramolecular architectures. In particular, we will focus on understanding the relationship between bipolaron formation mechanism, molecular design and supramolecular architectures while measuring the magnetoresistance in polymer films realized through layer-by-layer vertical structures where the effect of the system dimensionality from 2D (single monolayer) up to 3D (multilayered film) will be explored at low temperature (down to 4 K) and high magnetic fields (up to 7 T). Furthermore, unraveling the role of the intrachain vs. interchain hopping rate in quasi-1D semiconducting wires and its related effect on inducing spin blockade in such supramolecular architectures will be investigated.