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二维材料在器件中的电荷和自旋输运，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/半导体或分子非共价晶格等2D共价键合（半）导体的界面。界面是我的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）局部能带形状，（iii）电荷和自旋输运（iv）光学性质，最终（v）该研究计划将关注的材料类中的器件物理。控制此类界面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（SL）在二维材料（如石墨烯或过渡金属二硫属化物（TMDC））上形成的杂化货车德瓦尔斯异质结构。与最近提出的货车德瓦尔斯异质结构形成的共价键合的二维材料通过弱相互作用结合在一起，在我的研究计划中，我将探索新的物理场景中出现的混合系统形成的二维SL在石墨烯或TMDC。特别感兴趣的将是SL在石墨烯和TMDC上产生周期性电势的效果，因为这样的周期性电势可以通过分子设计预编程并且以原子精度控制。裁剪这样的周期势是新颖的，并且是当前2D材料物理中的热门话题。此外，我们还将在低温和高磁场下，通过电学表征研究含重原子分子的超晶格对石墨烯介观特性的影响，探索叠加超晶格对石墨烯和TMDC量子指纹（如量子霍尔、舒布尼科夫-德哈斯振荡和弱（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，理解和控制超分子组装有机半导体中的自旋混合规则和磁电阻。特别是，我们将重点了解双极化子形成机制之间的关系，分子设计和超分子结构，同时测量聚合物薄膜中的磁电阻，通过逐层垂直结构实现，其中系统维度的影响从2D将在低温（低至4 K）和高磁场（高达7 T）下探索（单层）至3D（多层膜）。此外，解开链内与链间跳跃率在准一维半导体线中的作用及其在这种超分子结构中诱导自旋阻滞的相关影响将被研究。

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.