Photoactive Ionically Bonded Organic Metal Halide Hybrids

新功能材料是推动对我们日常生活有用的技术进步的关键之一。有机金属卤化物杂化物是一种新兴的功能材料，在发光二极管和辐射探测器等许多领域都有潜在的应用。在材料研究部固态与材料化学项目的支持下，马必武教授和他的研究团队致力于开发和研究具有独特晶体结构的新型有机金属卤化物杂化体。该团队将专注于具有多种独特化学和物理性质的“零维结构”。该项目的预期成果包括在原子/分子水平上对物质和材料过程的基本理解和控制能力，以及混合材料的宏观功能特性。本项目纳入了各种教育和外联活动，例如(i)促进对毕业生和本科生的多学科研究教育和培训，特别是那些来自代表性不足群体的学生；（ii）通过夏季青年学者计划、科学展览等方式，吸引K-12学生和公众参与。技术描述有机-无机金属卤化物杂化材料因其卓越的光学和电子特性而受到广泛关注，并在许多领域得到应用。除了众所周知的三维（3D）卤化物钙钛矿结构外，有机金属卤化物杂化物还可以具有许多其他晶体结构，其中金属卤化物单元，例如金属卤化物八面体，可以形成零（0D），一维（1D），二维（2D）结构。这些低维杂化材料表现出与三维金属卤化物钙钛矿完全不同的独特而显著的性能。本项目由材料研究部固态与材料化学项目支持，旨在通过各种合成方法设计和合成新的0D有机金属卤化物杂化物，更好地了解结构-性能关系，探索材料集成与潜在的技术创新，推进有机金属卤化物杂化物的研究。不同于以往的研究主要集中在包含绝缘有机阳离子的单组分系统上，研究小组研究了包含各种类型的有机成分（绝缘和半导体）和金属卤化物（分子物种和多核簇）的多组分系统。这些0D有机金属卤化物杂化体提供了一个强大的平台，可以解开有机和金属卤化物的隐藏性质，并研究重要的物理现象和过程，包括电子能带形成、激子-晶格耦合、电荷/能量转移、金属卤化物的激发态结构重组，以及有机分子性质对其分子包装的依赖。探索它们在各种类型的设备中的应用，如x射线闪烁体和探测器，为混合材料带来了新的机会。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical DescriptionNew functional materials are one of the keys to the advancement of technologies useful for our daily life. Organic metal halide hybrids, in which organic and metal halide ions form ionically bonded single crystals, are an emerging class of functional materials that have potential applications in many areas, such as light emitting diodes and radiation detectors. In this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, Prof. Biwu Ma and his research team aim to develop and study new organic metal halide hybrids with unique crystalline structures. The team will focus on “zero-dimensional structures” which possess diverse and unique chemical and physical properties. The expected outcomes of this project include fundamental understanding and ability of controlling matter and material processes at the atomic/molecular level, as well as macroscopic functional properties of hybrid materials. Various educational and outreach activities are integrated in this project, for instance, (i) promoting multidisciplinary research education and training to graduates and undergraduate students, in particular those from underrepresented groups; (ii) involving K-12 students and general public through summer young scholar programs, scientific exhibitions, etc.Technical DescriptionOrganic-inorganic metal halide hybrid materials have attracted great research attention for their remarkable and useful optical and electronic properties with applications in a variety of areas. In addition to the well-known three-dimensional (3D) halide perovskite structure, organic metal halide hybrids can have many other crystallographic structures, in which metal halide units, for instance, metal halide octahedrons, form zero- (0D), one- (1D), two- dimensional (2D) structures. These low dimensional hybrid materials exhibit unique and remarkable properties that are completely different from those of 3D metal halide perovskites. This project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, aims to advance the research on organic metal halide hybrids, through designing and synthesizing new 0D organic metal halide hybrids via various synthetic approaches, gaining better fundamental understanding of the structure-property relationships, and exploring material integration with potential technological innovations. Unlike previous efforts mainly focusing on single component systems containing insulating organic cations, the research team investigates multicomponent systems that contain various types of organic components (both insulating and semiconducting) and metal halides (both molecular species and multinuclear clusters). These 0D organic metal halide hybrids serve as a powerful platform to unlock the hidden properties of both organic and metal halide species, and study important physical phenomena and processes, including electronic band formation, exciton-lattice coupling, charge/energy transfer, excited state structural reorganization of metal halides, as well as the dependence of the properties of organic molecules on their molecular packings. The exploration of their applications in various types of devices, such as X-ray scintillators and detectors, leads to new opportunities for hybrid materials.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.