CAREER: Exploring Luminescence in Low-Dimensional Halides

由于发光材料在最先进的灯具、显示器（如电视、监视器）和医疗扫描仪中的应用，以及它们在光学设备和生物医学领域的潜力，发光材料继续在现代社会中发挥重要作用。发光材料的重要性已经得到了全球的认可，联合国将2015年定为国际光与光基技术年。为了进一步说明这一点，据估计，节能的固态照明（例如，led）可以在2035年减少75%的照明能源使用。在由材料研究部固态和材料化学项目和促进竞争研究（EPSCoR）建立的项目共同支持的CAREER奖中，Bayram Saparov教授和他的团队旨在开发一种新型的价格合理，易于制备，地球丰富且坚固的基于廉价金属卤化物的发光材料。该项目对理解金属卤化物的发光特性和原子结构之间的联系具有潜在的变革性影响。反过来，这将使我们能够控制和操纵卤化物的材料化学，以制备具有全范围颜色可调性的定制设计发光材料。除了节能固态照明技术的全新途径外，该项目还将通过我们的高中生研究经验（REHSS）计划，为促进材料化学研究和在俄克拉荷马州发展多样化，有竞争力的科学，技术，工程和数学（STEM）劳动力提供一个极好的平台。REHSS计划将为俄克拉何马州的高中生提供一个真正的两个月的研究经验；参与者包括主要为少数民族社区服务的偏远农村学校。技术概述：近年来，全无机卤化铜由于其低成本、丰富的化学成分、溶液可加工性和创纪录的高发光效率而成为光学应用的优秀候选者。这些卤化铜具有独特的能带结构，其中铜(I)轨道主导了带隙周围的状态，导致其光致发光性能的可调性较差。该奖项由材料研究部固态与材料化学项目和促进竞争研究的既定项目（EPSCoR）共同支持，Bayram Saparov教授和他的团队将通过对拟议系统中化学成分-结构-性质关系的基本理解，开发新的策略来控制铜和银卤化物的结构和发光特性。所提出的卤化物的低维晶体结构具有窄的离散能带，强电荷局域化和高激子结合能的特点，并应使其成为高效的发光体。这些努力将为更广泛的协同研究和教育计划提供核心构建块，旨在促进材料化学研究，并在俄克拉荷马州发展多样化、有竞争力的STEM劳动力。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 SUMMARY Luminescent materials continue to play a major role in modern society owing to their applications in the state-of-the-art lamps, displays (e.g., TVs, monitors) and medical scanners, and to their potential in the fields of optical devices and biomedicine. The importance of luminescent materials has been recognized globally, designated by the United Nations, 2015 was celebrated as the International Year of Light and Light-based Technologies. To further illustrate this, it is estimated that energy-efficient solid-state lighting (e.g., LEDs) could reduce lighting energy use by 75% in 2035. In this CAREER award, jointly supported by the Solid State and Materials Chemistry program in the Division of Materials Research and the Established Program to Stimulate Competitive Research (EPSCoR), Prof. Bayram Saparov and his group aim to develop a new type of affordable, easy-to-prepare, earth-abundant and robust luminescent materials based on inexpensive metal halides. The project has a potential transformative impact on understanding of the links between the light emission properties and atomic structures of metal halides. This, in turn, will allow us to control and manipulate the materials chemistry of halides to prepare custom design light-emitting materials with full range color-tunability. In addition to brand new avenues for energy-saving solid-state lighting technologies, this project will also provide an excellent platform for promoting materials chemistry research and developing a diverse, competitive Science, Technology, Engineering, and Mathematics (STEM) workforce in Oklahoma through our Research Experience for High School Students (REHSS) program. The REHSS program will provide a real two-month research experience for Oklahoma high school students; participants include remote rural schools that are primarily serving minority communities. TECHNICAL SUMMARYAll-inorganic copper halides have recently been reported as excellent candidates for optical applications owing to their low cost, earth-abundant chemical compositions, solution processability and record high luminescence efficiencies. These copper halides have unique band structures in which copper(I) orbitals dominate the states around the bandgap, which result in poor tunability of their photoluminescence properties. With this CAREER award, jointly supported by the Solid State and Materials Chemistry program in the Division of Materials Research and the Established Program to Stimulate Competitive Research (EPSCoR), Prof. Bayram Saparov and his group will develop new strategies to control the structures and light emission properties of copper and silver halides through a fundamental understanding of chemical composition-structure-property relationships in the proposed systems. Low-dimensional crystal structures of the proposed halides exhibit narrow discrete energy bands, strong charge localization and high exciton binding energies, characteristics and should enable their performance as highly efficient light emitters. These efforts will provide a core building block of a broader, synergistic research and education program aimed at promoting materials chemistry research and developing a diverse, competitive STEM workforce in Oklahoma.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.