CAS: Harvesting Electrons From Lower Energy Excited States to Extend Spectral Coverage and Facilitate Multiple Charge Collection Following Singlet Fission on Metal Oxides

CAS：从较低能量激发态收集电子以扩展光谱覆盖范围并促进金属氧化物上单线态裂变后的多重电荷收集

• 批准号: 2247164
• 负责人: David Blank
• 金额: $ 20万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247164&HistoricalAwards=false
• 关键词: CAS; Harvesting; Electrons; Lower; Energy

With support from the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, Professors Blank and Gladfelter from the University of Minnesota-Twin Cities and Professor Pappenfus from the University of Minnesota-Morris seek to build a more thorough understanding of how light can be used to induce separation of charge, a critical first step in the conversion solar energy into electrical or chemical energy. In addition to photovoltaic devices, light-induced charge transfer is part of other devices such as sensors. This project will focus on using well-defined nanocrystals of metal oxides as the scaffold for probing this behavior. A better understanding of how to leverage metal oxide semiconductors is expected to contribute to the development of a range of optoelectronic devices and to improving the efficiency of such devices. This project will directly support the training and education of the next generation of physical/physical organic chemists, including graduate students and undergraduate students, in areas of chemistry that cross the traditional disciplinary boundaries. The University of Minnesota-Morris is a rural, primarily undergraduate institution, and this project will provide undergraduate students at Morris with a collaborative research experience.Nanocrystalline films of semiconducting metal oxides often play a central role in devices that involve the separation of charge. Commonly employed metal oxides have conduction band energies that place thermodynamic and kinetic limitations on the molecules used as sensitizers. Indium oxide has yet to receive much attention, but it has tremendous potential. With a lower energy conduction band, it opens a new window of opportunity to access lower energy sensitizer states. This window would, in principle, allow extension of the spectrum of light that can be harvested and provide access for charge transfer from lower energy triplet states of the sensitizers. The triplet states that are of particular interest in this proposal are those that are generated via singlet fission. This project will use transparent solution phase dispersions of nanocrystals with narrow size distributions as a well-defined experimental platform to investigate the excited state dynamics and charge transfer of the sensitizer. The goal is to realize, characterize and optimize charge multiplication through singlet fission on a transparent metal oxide surface with the potential to increase the efficiency of light harvesting.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.

在化学部的化学结构，动力学和机制-B计划的支持下，明尼苏达大学 - 汤因城市的Blank和Gladfelter教授和明尼苏达州摩尔斯大学的Pappenfus教授寻求更彻底地了解如何使用光线来诱导电荷分离的光线，这是对转换式溶剂能量的关键第一步，将其用于电子或化学能量。除了光伏设备外，光诱导的电荷转移是其他设备（例如传感器）的一部分。该项目将着重于使用定义明确的金属氧化物纳米晶作为探测这种行为的脚手架。对如何利用金属氧化物半导体的更好理解有望有助于一系列光电设备的开发并提高此类设备的效率。该项目将直接支持跨越传统学科界限的化学领域，包括研究生和本科生在内的下一代物理/物理有机化学家，包括研究生和本科生。明尼苏达州莫里斯大学是一家农村，主要是本科生，该项目将为莫里斯的本科生提供协作研究经验。半导体金属氧化物的纳米晶电影通常在设备中起核心作用，涉及涉及电荷分离的设备。通常使用的金属氧化物具有传导带能量，可将热力学和动力学限制放在用作敏化剂的分子上。氧化二氮尚未受到很多关注，但它具有巨大的潜力。通过较低的能量传导带，它为访问较低能量敏化器状态的新机会窗口打开了。原则上，此窗口将允许延长可以收获的光谱，并提供从敏感器较低能量三重态的电荷传递的访问。在该提案中特别感兴趣的三胞胎状态是通过单线裂变产生的三胞胎状态。该项目将使用具有狭窄尺寸分布的纳米晶体的透明溶液相分散，作为一个定义明确的实验平台，以研究激发态动力学和敏感器的电荷传递。目的是通过在透明的金属氧化金属表面上进行单线裂变来实现，表征和优化电荷乘积，并有可能提高收获光的效率。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准通过评估来通过评估来获得支持的。