超快相干光电转换的探索

项目名称： 超快相干光电转换的探索

项目编号： No.91233103

项目类型： 重大研究计划

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 张春峰

作者单位： 南京大学

项目金额： 80万元

中文摘要： 最近研究发现,量子相干性可极大提高界面间能量转移效率,是光合作用体系光电转换内量子效率极高的关键原因。本项目将尝试将量子相干光电转换的概念引入到人工材料中，利用量子相干性提高转换效率，探索突破Shockley-Queisser极限的基本原理，寻求实现量子光电转换的器件方案。项目将利用相干性优化界面能量电荷转移，提高速率至亚皮秒时间尺度，以克服皮秒或更长时间尺度的电声子作用、俄歇复合等引起Shockley-Queisser极限的物理过程。为此，项目将采用超快相干光谱学方法，在纳晶敏化电池和聚合物电池两类体系内，分别探索热电子转移和激子迁移过程中的超快量子相干特征，寻求通过微纳结构设计电子能级、调控光子吸收、优化相干转移的量子相干光电转换器件的设计方案。量子相干光电转换的实现，将克服电声子作用引起的热损失，突破Shockley-Queisser极限，全面提高转换效率,发展量子绿色能源。

中文关键词： 光电转换；超快光谱；单线态分裂；三阶非线性；

英文摘要： Recent researches suggest a significant contribution of quantum coherence to the high internal quantum efficiency of solar conversion in photosynthesis complex. Quantum coherence plays a key role in the ultrafast and highly-efficient interfacial electronic energy transfer between the molecules in the light harvesting systems and reactions centers. In this project, we propose to investigate quantum coherence in photoelectric conversion processes in artificial materials. The aim of this proposal is to study the basic principles that can aid to design quantum-coherent solar conversion devices with potential of beating the Shockley-Queisser limit. With this purpose, we''ll try to push the rate of interfacial energy and charge transfer to the scale of sub-picosecond with quantum coherence. This efficient interfacial transfer can eliminate the energy loss associated to the slower processes like electron-phonon interaction and Auger recombination that lead to the Shockley-Queisser limit. We''ll perform study with the technique of ultrafast quantum coherent spectroscopy. With two representative systems of nanocrystal-sensitized solar cells and polymer solar cells, we''ll identify the quantum coherent effect in the processes of hot-electron transfer and intrachain exciton migration, respectively. With the new ac

英文关键词： Soler conversion；Ultrafast spectroscopy；Singlet fission；Third order nonlinearity；