Developing self-assembly strategies for the fabrication of well-defined and large area 2D coordination polymers

拓扑材料的设计吸引了巨大的研究兴趣，因为它有可能获得新的和奇异的物理现象，如Mott转变、高温超导、拓扑绝缘体、巨磁电阻和巨磁电效应，这些可以用来实现无耗散量子电子态。在材料研究部固态和材料化学项目的支持下，犹他大学的Luisa Whitakker-Brooks教授和她的团队将研究和解决与2D配位聚合物(2DCP)的合成和结晶度相关的挑战，以实现其作为拓扑材料的潜在应用。其目的是开发合成路线和自组装策略，从而在大面积范围内获得结晶度可控的无缺陷2DCP薄膜。因此，通过将计算模拟和实验技术相结合，本研究旨在确定在2DCP合成过程中导致缺陷形成的动力学瓶颈。这一综合方法提供了对影响2DCP形成和性质的因素的全面了解，不仅有利于目标材料，而且可能有助于更广泛的2DCP家族。此外，该研究项目旨在创建一个包含2DCP的电子结构和预测量子性质的数据库。该数据库将有助于对2DCP的理解和表征，并可作为未来量子电子学研究的宝贵资源。更广泛的社区通过执行两项外联活动参与进来：(1)“De la Mano de la Ciencia en el Valle”(译文：硅谷的科学前沿)系列研讨会，作为向犹他州山谷的拉美裔人口宣传和分享尖端科学成果的手段，以及(2)通过参加犹他大学中学教师科学硕士计划(MSSST)，培训高中教师并帮助制定教学课程。晶体二维配位聚合物(2DCP)被预测为一种拓扑材料，包括量子自旋/反常霍尔绝缘体、拓扑平带和具有一系列电磁特性的超导体，这些都是实现新型量子信息系统所必需的。2DCP提供了一个可调节的材料平台，其中构建块的分子结构和它们形成的晶体的几何形状可以使用有机化学的方法来设计。然而，到目前为止，对这些材料的实验研究还没有证实它们预测的量子性质。2DCP作为拓扑材料性能不佳的主要原因是其结晶度较差。如果要实现2DCP作为拓扑材料的潜力，就需要找到制备结晶度显著提高的薄膜的合成路线。该项目由NSF材料研究部的固态和材料化学计划支持，旨在通过计算和实验相结合的方法确定导致2DCP合成中缺陷形成的微观动力学瓶颈。对缺陷形成过程的洞察被应用于开发新的自组装策略，允许形成长度超过数十微米的无缺陷的2DCP薄膜，从而释放其作为拓扑材料的理论潜力。拟议研究工作的好处和成果包括：(1)开发能够制备大面积、高度定向的具有可控缺陷态的2DCP薄膜的合成协议；(2)创建建议的2DCP的电子结构和预测的量子性质的数据库；(3)基于分子动力学模拟和实验数据的自组装策略的制定，可能应用于更广泛的2DCP家族；以及(4)阐明建议的2DCP的电子、热和光学性质以及它们在量子信息科学中的应用途径。本研究中提出的合成-表征-器件物理协议定义了工具箱，使我们能够实现面向量子电子技术的合理材料设计的目标。所获得的知识和开发的工具有利于研究用于发光二极管、薄膜晶体管和光伏的n型有机材料的平行领域。该研究项目为研究生和本科生以及拥有密切指导专业经验的高中生和教师提供独特的材料化学和器件制造方面的跨学科培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical SummaryThe design of topological materials is attracting enormous research attention due to the possibility of accessing novel and exotic physical phenomena such as Mott transitions, high-temperature superconductivity, topological insulators, colossal magnetoresistance, and giant magneto-electric effects, which can be used to achieve dissipation-less quantum electronic states. With support from the Solid State and Materials Chemistry program in the Division of Materials Research, Prof. Luisa Whitakker-Brooks and her group at the University of Utah will investigate and address the challenges associated with the synthesis and crystallinity of 2D coordination polymers (2DCPs) for their potential application as topological materials. The aim is to develop synthetic routes and self-assembly strategies that can lead to defect-free 2DCP thin films with controlled crystallinity over large areas. As such, by combining computational simulations and experimental techniques, the research aims to identify the kinetic bottlenecks that contribute to defect formation during the synthesis of 2DCPs. This integrated approach provides a comprehensive understanding of the factors influencing the formation and properties of 2DCPs, not only benefiting the targeted materials but also potentially contributing to the broader family of 2DCPs. Additionally, the research project aims to create a database of electronic structures and predicted quantum properties comprising 2DCPs. This database will contribute to the understanding and characterization of 2DCPs and can serve as a valuable resource for future studies in quantum electronics. The broader community is engaged by executing two outreach activities: (1) “De la Mano de la Ciencia en el Valle” (translation: Science Frontiers in the Valley) seminar series as a means to promote and share cutting-edge science results with the Hispanic population in the Utah Valley and (2) Training high-school teachers and aiding in the development of teaching curricula through participation in the Master of Science for Secondary School Teacher (MSSST) program at the University of Utah. The latter allow for training teachers and students on materials synthesis and device fabrication to strengthen the microelectronic workforce.Technical SummaryCrystalline 2D coordination polymers (2DCPs) have been predicted to be topological materials, including quantum spin/anomalous Hall insulators, topological flat bands and superconductors with a range of electromagnetic properties essential for the realization of novel quantum information systems. 2DCPs provide a tunable material platform wherein the molecular structure of building blocks and the geometry of the crystals they form can be designed using methods of organic chemistry. However, experimental studies of these materials have so far failed to confirm their predicted quantum properties. The main reason for the disappointing performance of 2DCPs as topological materials is their poor crystallinity. If the potential of 2DCPs as topological materials is to be realized, synthetic routes to thin films with markedly improved crystallinity need to be found. This project, supported by the Solid State and Materials Chemistry program in the NSF’s Division of Materials Research, seeks to identify the microscopic kinetic bottlenecks that lead to defect formation in the synthesis of 2DCPs with an integrated computational and experimental approach. The generated insight into defect formation processes is applied to develop new self-assembly strategies that allow the formation of 2DCP thin films that are defect-free over length scales exceeding tens of microns, thus unlocking their theoretical potential as topological materials. The benefits and outcomes of the proposed research efforts include (1) The development of synthetic protocols that allow for the fabrication of large-area, highly oriented 2DCP thin films with controlled defect states; (2) The creation of a database of electronic structures and predicted quantum properties of proposed 2DCPs; (3) Formulation of self-assembly strategies backed by molecular dynamics simulations and experimental data with potential application to the broader family of 2DCPs; and (4) Elucidation of electronic, thermal, and optical properties of proposed 2DCPs with a route to their application in quantum information science. The synthesis-characterization-device physics protocols proposed in this research program define the toolbox that allow us to fulfill the goal of rational materials design towards quantum electronic technologies. The knowledge gained and tools developed benefit parallel fields investigating n-type organic materials for light-emitting diodes, thin-film transistors, and photovoltaics. This research project provides unique cross-disciplinary training in materials chemistry and device fabrication to graduate and undergraduate students as well as high-school students and teachers with a closely mentored professional experience.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.