Singlet Fission for Highly Efficient Organic Photovoltaics

用于高效有机光伏的单线态裂变

• 批准号: 1214131
• 负责人: Charles Musgrave
• 金额: $ 30.18万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1214131&HistoricalAwards=false
• 关键词: Singlet; Fission; Highly; Efficient; Organic

The Chemical Structure, Dynamics, and Mechanism program in the Chemistry Division of the National Science Foundation supports Professor Charles Musgrave of the University of Colorado Boulder to lead two closely related research efforts on singlet fission (SF) and spin controlled exciton diffusion (SCED) in organic photovoltaic (PV) materials. This effort focuses on using computational quantum chemistry to explore the fundamental principles involved in these two research thrusts to discover and understand phenomena that might be exploited in future technological applications. The project aims to understand the mechanisms of SF and SCED and the principles that govern these processes. SF involves absorbing a solar photon to create a singlet exciton, or bound electron-hole pair and then splitting this exciton into two coupled triplet excitons of lower energy. The motivation for SF is the ability to absorb high-energy photons and down convert their energy with little loss whereas the excess energy of the high-energy photon would usually be dissipated through conversion into heat. Thus, if successful, SF could lead to more efficient solar cells. A key to this process is the possible role of an optically dark multiexcitonic state in the exciton fission process. A major thrust of this project is to explore the nature of this dark state in various organic PV materials and to determine its role in governing the SF process. SCED is a proposed phenomena that may affect the rate at which excitons, and thus energy is transported in organic PV where the exciton transfer rate from molecule to molecule is affected by a local magnetic field through spin-orbit coupling to create excitons that are no longer Born-Oppenheimer pure spin states, but which can be quickly transported to harvest their energy before they undergo non-radiative decay to dissipate their energy. If the transport rate can be accelerated, it offers the potential to create significantly thicker PV films that could capture a larger fraction of the energy contained in solar radiation. The goal of this project is to elucidate the governing principals of these processes to predict, discover and understand new SF and SCED materials that can lead to new, more efficient solar cells. These same phenomena might also be exploited to obtain more efficient and environmentally friendly LED lighting. The work also aims to integrate research with education and outreach to disseminate the new knowledge obtained through this research and to educate future technology workers and non-experts about the nature of interconverting solar energy into electrical energy for PVs. Ultimately, this project aims to prepare diverse undergraduate and graduate students for innovative and productive academic, industrial, government laboratory careers.

美国国家科学基金会化学部的化学结构，动力学和机制计划支持科罗拉多大学博尔德分校的Charles Musgrave教授领导两项密切相关的研究工作，即有机光伏（PV）材料中的单线态裂变（SF）和自旋控制激子扩散（SCED）。这项工作的重点是使用计算量子化学来探索这两个研究重点中涉及的基本原理，以发现和理解可能在未来技术应用中被利用的现象。该项目旨在了解SF和SCED的机制以及管理这些过程的原则。SF涉及吸收太阳光子以产生单重态激子或束缚电子-空穴对，然后将该激子分裂成两个耦合的较低能量的三重态激子。SF的动机是能够吸收高能光子并将其能量向下转换而几乎没有损失，而高能光子的多余能量通常会通过转换为热量而消散。因此，如果成功的话，SF可能会导致更高效的太阳能电池。这个过程的关键是在激子裂变过程中的光学暗多激子状态的可能作用。该项目的主要目的是探索各种有机光伏材料中这种暗态的性质，并确定其在控制SF过程中的作用。SCED是一种提出的现象，其可以影响激子的速率，并且因此影响能量在有机PV中传输，其中激子从分子到分子的传输速率通过自旋-轨道耦合受到局部磁场的影响，以产生不再是Born-Oppenheimer纯自旋态的激子，但是激子可以在它们经历非辐射衰变以耗散它们的能量之前被快速传输以收获它们的能量。如果传输速率可以加快，它提供了创造更厚的PV薄膜的潜力，可以捕获太阳辐射中包含的更大部分能量。该项目的目标是阐明这些过程的管理原则，以预测，发现和理解新的SF和SCED材料，从而产生新的，更高效的太阳能电池。这些相同的现象也可以被利用来获得更高效和环保的LED照明。 这项工作还旨在将研究与教育和推广相结合，以传播通过这项研究获得的新知识，并教育未来的技术工作者和非专家关于太阳能转换为光伏发电的性质。最终，该项目旨在为不同的本科生和研究生准备创新和富有成效的学术，工业，政府实验室职业。