Collaborative Research: The Impact of Mesoscale Structure on Multiexciton Dynamics of Macromolecules

这个合作项目研究有机聚合物如何设计用于下一代太阳能电池和其他光活性电子设备的细节。一种有希望但未经证实的有效利用光能的方法涉及一种特殊类型的有机分子，当适当组装时，可以回收通常作为热量损失的能量。然而，以最佳方式组织这些分子已被证明是一项挑战，以至于这种方法的有益影响迄今尚未实现。这个项目开发了一种新的方法来组装光收集分子，使它们以刷子状的排列方式组织起来。研究人员使用超高速相机来研究组件的能量流动，并利用这些信息来优化它们的结构。从这些研究中得出的发现可能会带来能源和信息应用的变革性技术。合作为参与的学生提供了机会：发展跨学科沟通技能；团队合作；解决各自核心学科以外的挑战；向化学家、物理学家和整个社区传播他们的发现。主要调查人员侧重于针对纽约州哈莱姆区面临社会经济困难的社区以及年轻的化学家和博士后科学家的外联活动，特别侧重于那些在科学中代表性不足的群体。多激子产生现在是光物理学中一个快速增长的领域，还没有被敏锐地理解。多激子产生的分子版本是单态裂变--从单个光子产生两个独立的三重态激子。从这种光捕获机制可以预见，非传统的激子动力学可以利用a)当两个激子/载流子从一个光子(光电子学)产生时所产生的放大特性，b)自旋关联量子态的快速布居(量子信息)，或c)局域多电子反应中心的激活(光化学和光催化)。这一建议植根于对有机大分子结构-性质关系的基础研究，这些关系支配着未来在设备体系结构中实现所需的单重态裂变多激子动力学。研究人员使用分子工程方法来控制基本的多激子动力学和激子在多个长度尺度上的传输-从单个分子(三重态对形成过程)到纳米/微尺度(自由三重态的形成和传输)。了解发色团本身的化学性质及其空间排列的影响，在战略上拴在大分子内，提供了必要的基本信息，以解决开发下一代单线态裂变装置概念中的一些统一和固有的挑战。该奖项反映了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。

This collaborative project studies intimate details of the way organic polymers can be designed for uses in next-generation solar cells and other light-active electronic devices. One promising but unproven way of harnessing light-energy efficiently involves a special class of organic molecules that, when properly assembled, can recover energy that is normally lost as heat. However, organizing these molecules in the optimal way has proven to be a challenge, such that the beneficial impacts of this approach have not been realized to date. This project develops a new approach to assembling light harvesting molecules so that they are organized in a brush-like arrangement. The researchers use ultrafast cameras to study the flow of energy of the assemblies and use this information to optimize their structures. The discoveries that ensue from these studies can lead to transformative technologies for energy and information applications. The collaboration provides the participating students with opportunities to: develop interdisciplinary communication skills; work in teams; tackle challenges outside their respective core subject; disseminate their findings to chemists, physicists, and the community as a whole. The principal investigators focus on outreach activities targeting socioeconomically challenged communities in Harlem, NY, as well young chemists and postdoctoral scientists, with particular emphasis on those who belong to under-represented groups in science. Multiple exciton generation is now a rapidly growing area in photophysics that has yet to be acutely understood. The molecular version of multiple exciton generation is singlet fission – the generation of two independent triplet excitons from a single photon. From this light harvesting mechanism, unconventional exciton dynamics can be envisioned to exploit a) the amplification properties that result when two excitons/charge carriers are created from one photon (optoelectronics), b) the rapid population of spin correlated quantum states (quantum information), or c) the activation of localized multielectron reaction centers (photochemistry and photocatalysis). This proposal is rooted in fundamental studies of organic macromolecule structure-property relationships that govern the singlet fission multiexciton dynamics necessary for future implementations in device architectures. The researchers use a molecular engineering approach to control fundamental multiexciton dynamics and exciton transport across multiple length scales – from individual molecules (triplet pair formation processes) to nano-/micro-scales (free triplet formation and transport). Understanding the influence of the chemical nature of the chromophores themselves and their spatial arrangement, strategically tethered within macromolecules, provides the fundamental information necessary to solve some of the unifying and inherent challenges in developing next generation singlet fission device concepts.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.