Charger transfer at interfaces studied with non-linear infrared probes

在这个由美国国家科学基金会化学部化学结构、动力学和机制项目资助的项目中，来自威斯康星大学麦迪逊分校的Martin Zanni教授将利用二维红外（2D IR）和外差和频率产生（SFG）光谱来研究分子/半导体界面上的电子转移。这一过程是太阳能到电和太阳能到燃料转换过程中最基本的方面之一，但由于在界面上表征分子结构的困难，仍然没有完全理解。这些技术将用于解决多种染料构象，通过测量各自交叉峰的时间依赖性来绘制它们的个体动力学，并通过测量单晶界面上分子键的角度来确定它们的构象。该提案的广泛影响包括在这个多学科领域培训本科生和研究生，在国家ACS会议上传播我们的结果，并通过评审出版物，以及建立一个网站，使其更容易和有效地了解多维光谱学的最新发展。目标是提供以前无法实现的界面电荷转移的分子细节水平，从而更好地理解分子-半导体界面上的电荷分离和转移，这对于合理设计有机染料和量子点敏化太阳能和燃料电池是必要的。

In this project, funded by the Chemical Structure, Dynamics and Mechanisms program of the NSF Chemistry Division, Professor Martin Zanni from the University of Wisconsin-Madison will utilize two-dimensional infrared (2D IR) and heterodyned sum-frequency generation (SFG) spectroscopies to study electron transfer across molecule/semiconductor interfaces. This process is one of the most fundamental aspects of solar-to-electrical and solar-to-fuel conversion processes, but is still not fully understood largely due to the difficulties in characterizing molecular structures at interfaces. These techniques will be used to resolve multiple dye conformations, map their individual kinetics by measuring the time-dependence of their respective cross peaks, and determine their conformations by measuring the angles of molecular bonds on single crystal interfaces. The broader impacts of this proposal include the training of undergraduates and graduate students in this multi-disciplinary field, the dissemination of our results at national ACS meetings and through refereed publications, and the development of a website to make it easy and efficient to keep up-to-date on developments in multidimensional spectroscopy. The goal is to provide a level of molecular detail not previously attainable for interfacial charge transfer, thereby leading to a better understanding of charge separation and transfer at molecule-semiconductor interfaces that is necessary for the rational design of organic dye- and quantum-dot sensitized solar and fuel cells.