Tuning the Photo-physics of Organic Semi-conductors using Morphological and Plasmonic Effects

利用形态和等离子体效应调整有机半导体的光物理

基本信息

批准号：
1900506
负责人：
Linda Peteanu
金额：
$ 52万
依托单位：
Carnegie-Mellon University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-05-15 至 2024-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900506&HistoricalAwards=false
关键词：
Tuning Photo physics Organic Semi

项目摘要

Polymers are long molecular chains formed by linking together many small molecules, called monomers. By varying the monomer's chemical structure, chemists can create polymers that absorb light, fluoresce, and conduct electricity, making them useful for cell phone displays, solar photovoltaics, and even in medical imaging. Despite these advantages, polymers degrade upon exposure to oxygen and light, and their fluorescence decreases when the chains pack together to form the films used in devices. With support from the Chemical Structure, Dynamics, and Mechanism A and Macromolecular, Supramolecular, and Nanochemistry Programs in the Division of Chemistry, Professor Linda Peteanu of Carnegie-Mellon University is addressing these challenges. Working with her students, she is using a wide array of spectroscopic tools to understand why polymer chains degrade less when placed onto metal films, as well as why their fluorescence is reduced when the chains pack together. The team's discoveries are helping chemists to create improved polymers for consumer electronics applications, which could have significant societal broader impact. The educational broader impacts lie in the training of students with expertise in optics and novel imaging methods. In addition, outreach to K-12 students and to the public demonstrate how light interacts with matter. The outreach activities and demonstrations developed as part of this award help young scientists visualize the connections between the microscopic and macroscopic worlds and help the general public appreciate how this fundamental connection has been critical in the development of many of the products they use in their everyday lives. This research focuses on conjugated semi-conducting oligomers, polymers and their aggregates. These materials demonstrate the remarkable ability to transport energy and charge over distances that are large compared to molecular scales. These properties, in addition to their emissivity, are important to applications ranging from opto-electronic devices, such as photovoltaics and light emitting diodes, to chemical sensors and biological labels. From a fundamental perspective, extended or electronically-delocalized structures, such as these polymers and their aggregates, are of interest because their electronic properties lie in the gap between those of small molecules and extended solids. The goals of this project are two-fold. The first is to perform a comprehensive investigation utilizing a variety of spectroscopic and imaging tools, molecular modeling, and synthetic modification to understand how the emission spectra, dynamics and yields are controlled by ground-state conformation and by the rates and efficiencies of intersystem crossing and internal conversion. The second is to explore the effects of two local environmental perturbations, solvent polarity and plasmonic field effects, on the fluorescence yield and the rates and efficiencies of singlet-triplet relaxation, energy transfer and charge separation. These data may yield a better understanding of how the structure, morphology, and local environment of this important class of materials can be optimized for existing and novel applications that require high emissivity and efficient charge transport.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.

聚合物是由许多小分子（称为单体）连接在一起形成的长分子链。通过改变单体的化学结构，化学家可以制造出吸收光、发出荧光和导电的聚合物，使其可用于手机显示器、太阳能光伏发电，甚至医学成像。尽管有这些优点，聚合物在暴露于氧气和光时会降解，并且当链堆积在一起形成设备中使用的薄膜时，它们的荧光会减弱。在化学系化学结构、动力学和机理 A 以及高分子、超分子和纳米化学项目的支持下，卡内基梅隆大学的 Linda Peteanu 教授正在应对这些挑战。她与学生一起使用各种光谱工具来了解为什么聚合物链在放置到金属薄膜上时降解较少，以及为什么当链堆积在一起时它们的荧光会减少。该团队的发现正在帮助化学家为消费电子应用创造改进的聚合物，这可能会产生更广泛的社会影响。更广泛的教育影响在于培养具有光学专业知识和新颖成像方法的学生。此外，还向 K-12 学生和公众展示了光如何与物质相互作用。作为该奖项的一部分开展的外展活动和演示帮助年轻科学家可视化微观世界和宏观世界之间的联系，并帮助公众了解这种基本联系对于他们日常生活中使用的许多产品的开发至关重要。本研究重点关注共轭半导体低聚物、聚合物及其聚集体。这些材料表现出在远距离传输能量和电荷的卓越能力，远距离分子尺度相比。除了发射率之外，这些特性对于从光电器件（例如光伏和发光二极管）到化学传感器和生物标签的应用也很重要。从基本角度来看，扩展或电子离域结构（例如这些聚合物及其聚集体）令人感兴趣，因为它们的电子特性位于小分子和扩展固体之间的差距。该项目的目标有两个。第一个是利用各种光谱和成像工具、分子建模和合成修饰进行全面的研究，以了解基态构象以及系间穿越的速率和效率如何控制发射光谱、动力学和产率。内部转换。第二个是探索两种局部环境扰动（溶剂极性和等离子体场效应）对荧光产率以及单线态-三线态弛豫、能量转移和电荷分离的速率和效率的影响。这些数据可以让我们更好地了解如何针对需要高发射率和高效电荷传输的现有和新颖应用来优化这一类重要材料的结构、形态和局部环境。该奖项反映了 NSF 的法定使命，并被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。