CAREER: Femtosecond Fluoresence Upconversion Studies of Charge Transfer Reactions in Nanocrystal-Based Photovoltaics

授予范德比尔特大学桑德拉·罗森塔尔博士的这一职业奖项得到了化学部先进材料项目的支持。研究的重点是纳米晶体光伏系统中电荷转移反应的飞秒荧光研究，目的是利用半导体纳米晶体中的量子限制来创造高速和高效的光伏。具体目标是确定和控制半导体纳米晶体中光生电子-空穴对的命运，确定纳米晶体向C60电子转移的速率和机理，确定纳米晶体向聚合物空穴转移的速率和机理，以及确定纳米晶体/C60/聚合物基光伏电池的理想纳米晶尺寸。要解决的基本问题将是在原子水平上表征半导体纳米晶体表面，以及表面态密度在载流子弛豫和电荷转移中所起的作用，量子受限半导体作为施主的系统中电荷转移的超快光谱，以及电活性聚合物中的电子转移。这项研究可能会影响和导致商业上可行的光伏和光电设备。除了让本科生参与上述研究外，职业奖励的教学部分还将通过建立综合分析-物理化学实验室和课程，促进本科生对化学系的广泛参与，并强调使用先进的光谱和表面显微镜仪器。

This CAREER award to Dr. Sandra Rosenthal at Vanderbilt University is supported by the Advanced Materials Program in the Chemistry Division. The focus of the research is femtosecond fluorescence studies of charge transfer reactions in nanocrystal-based photovoltaic systems with the goal of exploiting quantum confinement in semiconducting nanocrystals to create high speed and efficiency photovoltaics. Specific ojectives are to determine and control the fate of photocreated electron-hole pairs in semiconducting nanocrystals, to determine the rate and mechanism of nanocrystal to C60 electron transfer, to determine the rate and mechanism of nanocrystal to polymer hole transfer, and to determine the ideal nanocrystal size for nanocrystal/C60/polymer-based photovoltaics. Fundamental issues to be addressed will be characterization of semiconductor nanocrystal surfaces at the atomic level and the role surface density of states plays in carrier relaxation and charge-transfer, ultrafast spectroscopy of charge-transfer in systems where a quantum confined semiconductor serves as a donor, and electron transfer in electroactive polymers. This research could impact and lead to commercially viable photovoltaic and optoelectronic devices.Apart from involving undergraduates in the above research, the teaching component of the CAREER award will facilitate involvement of undergraduates in the Chemistry Department broadly through the establishment of integrated Analytical-Physical Chemistry labs and courses emphasizing use of advanced spectroscopic and surface microscopy instrumentation .