International Collaboration in Chemistry: A Theoretical Investigation Of The Role Of The Chemical Bond In The Raman And Fluorescence Response Of Molecule-Nanoparticle Hybrids

亚利桑那州立大学的Vladimiro Mujica得到了化学理论、模型和计算方法国际化学合作项目的资助，其合作伙伴奥赛巴黎大学的Arne Keller以及Osman Atabek和Monica Calatayd都得到了法国国家研究机构的资助。这是由美国国家科学基金会国际科学与工程办公室（OISE）共同资助的。本项目旨在从理论上研究分子和半导体纳米粒子之间的化学键对这些杂化系统的拉曼和荧光响应的影响。这些过程必须共同考虑，因为由于化学键的形成和界面电荷转移引起的中隙状态的出现，激发和衰变途径变得相互依赖，而中隙状态在光激发和电子注入纳米粒子中都起着重要作用。这涉及到拉曼散射和荧光的截面计算，基于系统的有效偶极矩的时间相关函数的性质。由于电子激发的能隙减小，重点是在杂化而不是在单独的组分中共振的过程。激光光激发同时激发电子空穴激子的产生并探测拉曼和荧光响应。通过开发可靠的程序来预测当激光照射到这些分子-纳米颗粒混合系统时所产生的光，人们将对生物传感器、太阳能电池和光催化的基本物理和化学过程有更深入的了解。这三个领域对于能源和健康相关研究以及新型光电装置和传感器的技术实施至关重要。该项目涉及法国和美国研究小组之间的强有力的国际科学合作，它还考虑与实验小组和人力资源形成积极合作。

Vladimiro Mujica at Arizona State University is funded by the Chemical Theory, Models and Computational Methods program in an International Collaboration in Chemistry, with partners Arne Keller at the University of Paris in Orsay as well as Osman Atabek and Monica Calatayd all funded by France's Agence Nationale de la Recherche. This is co-funded by the NSF Office of International Science and Engineering (OISE). This project aims at a theoretical investigation of the influence of the chemical bond between a molecule and a semiconducting nanoparticle on the Raman and fluorescence responses of these hybrid systems. These processes must be jointly considered, as the excitation and decay pathways become interdependent due to the appearance of midgap states, induced by the formation of the chemical bond and interfacial charge transfer that play a fundamental role in both photoexcitation and electron injection into the nanoparticle. This involves the calculation of the cross section for both Raman scattering and fluorescence, based on the properties of the time-correlation function of the effective dipole moment of the system. The emphasis is on processes that are resonant in the hybrid but not in the separate components, due to the reduction of the energy gap for electron excitation. Laser photoexcitation simultaneously provokes the creation of an electron-hole exciton and probes the Raman and fluorescence responses.By developing reliable procedures to predict the light that emerges when laser light shines on these molecule-nanoparticle hybrid systems, greater understanding will be obtained of the fundamental physical and chemical processes in bio-sensors and also in solar cells and photocatalysis. These three areas are crucial for energy and health-related research and for the technological implementation of new photovoltaic devices and sensors. The project involves a strong international scientific cooperation between teams of researchers in France and the U.S and it also contemplates active collaboration with experimental groups and human resources formation.