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

我的研究项目研究了分子和2D材料在器件中的电荷和自旋输运，特别关注了超分子控制异质界面，即2D共价键合(半)导体上的金属/半导体、介电/半导体或分子非共价晶格等界面所产生的影响。界面是我的研究计划中的一个关键元素，因为它们直接影响(I)导电性，(Ii)局部能带形状，(Iii)电荷和自旋输运(Iv)光学性质，并最终影响本研究计划将关注的材料类别中的(V)器件物理。控制这样的接口可以产生新奇和令人兴奋的物理场景。我的研究项目主要集中在：(1)二维超分子晶格(SLS)在石墨烯或过渡金属二卤化物(TMDCs)等二维材料上形成的杂化van der Waals异质结构。与最近提出的由多层共价键合的2D材料通过弱相互作用连接在一起形成的van der Waals异质结构不同，在我的研究计划中，我将探索由二维SLS在石墨烯或TMDC上形成的混合系统中出现的新的物理场景。特别令人感兴趣的是SLS在石墨烯和TMDCs上产生周期性势能的效果，因为这种周期性势能可以通过分子设计预先编程，并以原子的精度进行控制。剪裁这种周期性势能是一种新颖的方法，也是目前二维材料物理领域的研究热点。此外，我们还将研究含有重原子的分子对石墨烯介观性质的影响，在低温和强磁场下进行电学表征，以探索叠加的SLS对石墨烯和TMDCs的量子指纹的影响，如量子霍尔、Shubnikov-de Haas振荡和弱(反)局域化。(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阻。特别是，我们将重点了解双极化子形成机制、分子设计和超分子结构之间的关系，同时测量通过逐层垂直结构实现的聚合物薄膜的磁阻，其中将探索从2D(单层)到3D(多层膜)在低温(低至4K)和强磁场(高达7T)下的系统维度的影响。此外，我们还将研究准一维半导体导线中链内链与链间跳跃率之间的关系，以及它在这种超分子体系中诱导自旋阻塞的相关作用。

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.