Photoactive Ionically Bonded Organic Metal Halide Hybrids

非技术描述新型功能材料是推动日常生活所用技术进步的关键之一。有机金属卤化物杂化材料是一类新兴的功能材料，在发光二极管和辐射探测器等领域具有潜在的应用前景。在材料研究部固态和材料化学项目的支持下，马碧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材料。该团队将专注于拥有不同和独特的化学和物理性质的“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，以及杂化材料的宏观功能特性。这个项目结合了各种教育和推广活动，例如：(I)促进对研究生和本科生的多学科研究教育和培训，特别是对那些来自代表性不足群体的学生；(Ii)通过暑期青年学者计划、科学展览等，吸引K-12学生和普通公众。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化合物还可以具有许多其他的晶体结构，其中金属卤化物单元，例如金属卤化物八面体，形成零(0D)、一(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质。该项目得到材料研究部固态和材料化学项目的支持，旨在通过各种合成方法设计和合成新的零维有机金属卤化物杂化材料，更好地了解结构与性能的关系，探索材料集成与潜在的技术创新，从而推动有机金属卤化物杂化材料的研究。与以前主要关注包含绝缘有机阳离子的单组分体系不同，研究小组研究了包含各种类型的有机组分(绝缘和半导体)和金属卤化物(分子物种和多核簇合物)的多组分体系。这些零维有机金属卤化物杂化化合物为解开有机和金属卤化物物种的隐藏性质提供了一个强大的平台，并研究了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的性质与其分子堆积的关系。对它们在各种设备中的应用的探索，如X射线闪烁体和探测器，为混合材料带来了新的机会。这一奖项反映了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 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.