Low Dimensional Organometal Halide Perovskites

非技术性描述。新的功能材料是我们日常生活中有用技术进步的关键之一。有机金属卤化物钙钛矿是一类新兴的有机-无机杂化材料，在太阳能电池、发光二极管等光电子器件中具有潜在的应用前景。在这个项目中，研究小组的目标是开发和研究新型有机金属卤化物钙钛矿，具有传统钙钛矿中没有观察到的独特的晶体结构和性能。特别令人感兴趣的是低维有机金属卤化物钙钛矿，这些钙钛矿在很大程度上没有被研究界探索。该项目的预期成果包括对这类新材料的基本理解，以及开发具有新现象和优异性能的光电子器件功能材料的指导方针。该项目结合了各种教育和宣传活动，其中包括：(I)促进对毕业生和本科生进行多学科的研究、教育和培训，特别是对那些人数较少的群体的研究、教育和培训；(Ii)通过在塔拉哈西挑战者学习中心举办的“照明技术的演变”科学展览，让K-12学生和普通公众参与进来。技术说明。有机金属卤化物钙钛矿是一种晶体杂化材料，具有特殊的结构可调性。通过选择合适的无机和有机组分，可以通过无机单元、金属卤化物八面体在分子水平上精细地控制杂化材料的晶体结构，形成零(0D)、一(1D)、二维(2D)和三维(3D)结构。尽管在这类材料上做了大量的工作，但到目前为止，研究的重点主要集中在3D和2D钙钛矿上，对能够显示出与3D和2D钙钛矿显著不同的独特、显著和有用的性质的一维和零维钙钛矿的研究很少。在这个项目中，研究小组研究了具有一维和零维结构的新型低维有机金属卤化物钙钛矿，其中金属卤化物八面体分别连接在一个链状(1D)和完全相互隔离(0D)中。这项研究包括：(I)识别和理解与一维和零维钙钛矿材料的合成和加工有关的现象和机制；(Ii)表征这些新材料独特的结构、光学和电学性质，以从根本上了解其结构与性能的关系；(Iii)研究它们在光泵浦和电驱动发光二极管等光电子器件中的功能。该项目的成功将为新型有机-无机杂化材料的开发提供指导，从而在光电子器件中展示新的现象和优异的性能。在这个项目中获得的知识可以将经典的分子科学与固体物理联系起来，例如分子概念中的“激发态结构扭曲”和固体理论中的“激子自陷”，因为这些材料的构件可以被认为是分子物种或晶格点。

Non-technical Description. New functional materials are one of the keys to the advance of technologies useful in our daily life. Organometal halide perovskites are an emerging class of organic-inorganic hybrid materials that have potential applications in many optoelectronic devices, such as solar cells and light emitting diodes. In this project, the research team aims to develop and study new types of organometal halide perovskites with unique crystalline structures and properties that have not been observed in conventional ones. Of particular interest are low dimensional organometal halide perovskites that have been largely unexplored by the research community. The expected outcomes of this project include fundamental understandings of this new class of materials, and guidelines for the development of functional materials with new phenomena and superior performance for optoelectronic devices. Various educational and outreach activities are integrated in this project, including: (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 scientific exhibitions of "The Evolution of Lighting Technology at the Challenger Learning Center of Tallahassee. Technical Description. Organometal halide perovskites are crystalline hybrid materials with exceptional structural tunability. By choosing appropriate inorganic and organic components, the crystallographic structures can be finely controlled with the inorganic units, metal halide octahedrons, forming zero- (0D), one- (1D), two- (2D), and three-dimensional (3D) structures in the hybrids on molecular level. Despite a great deal of work conducted in this class of materials, the research focus to date has been mainly on 3D and 2D perovskites, with little done in 1D and 0D perovskites that can exhibit unique, remarkable and useful properties significantly different from those of 3D and 2D perovskites. In this project, the research team investigates new low dimensional organometal halide perovskites with 1D and 0D structures, in which the metal halide octahedrons are connected in a chain (1D) and completely isolated from each other (0D), respectively. The research involves (i) identification and understanding of phenomena and mechanisms associated with synthesis and processing of 1D and 0D perovskites, (ii) characterization of the unique structural, optical, and electronic properties of these new materials to gain a fundamental understanding of the structure-property relationship, and (iii) investigation of their functionalities in optoelectronic devices, such as optically pumped and electrically driven light emitting diodes. The success of this project can generate guidelines for the development of new organic-inorganic hybrid materials to exhibit novel phenomena and superior performance in optoelectronic devices. The knowledge gained in this project can relate the classic molecular science to solid-state physics, for instance "excited state structural distortion" in molecular concept to "exciton self-trapping" in solid state theory, as the building blocks of these materials can be considered as either molecular species or lattice points.