本项目提出以量子点超晶格为光吸收层，将一个高能光子转换为多个激子，产生载流子倍增效应，以期解决现有太阳电池器件对高能光子利用率不足的问题，这是一项近乎全新的探索。采用多种成膜技术可控制备量子点超晶格/TiO2复合膜，调控其微纳结构参量，增强量子点间波函数耦合作用，进而将高能光子产生的多激子快速转移至邻近量子点。这种点间激子快速转移使单个量子点内激子浓度大幅降低，可抑制俄歇复合效应、延长多激子的寿命，有望解决激子消逝过快较难提取利用的问题。以定量化的飞秒瞬态吸收光谱技术为手段，探明量子点超晶格微观结构与多激子产生、分离及传输之间的内在联系。揭示提高高能光子利用有效途径和规律，解决多激子太阳电池器件研制的科学技术问题，提供高效的太阳电池器件，获得创新性的研究成果。本项目对推动光电信息学、光电材料学、超快光子学等相关学科的交叉与发展具有重要的意义。

This project proposes a quantum dot superlattice as a photoactive layer to convert one high energy photon into multiple excitons, which is an almost fully new exploration. It aims at overcoming the insufficient utilization of those high energy photons of current solar cells by introducing this carrier multiplication effect. The microstructures of the complex superlattice film will be effectively controlled via various synthetic approaches in a bid to enhance the wave function coupling of adjacent quantum dots and thereby leading to a fast transfer of excitons generated from high energy photons from one quantum dot to its neighboring dot. The rapid exaction transfer between adjacent quantum dots will be a promising resolution to the short-lived excitons which are hard to be extracted, because the density of excitons in a single quantum dot is greatly reduced in this circumstance, which leads to a suppressed the Auger recombination and an extended lifetime of the excitons. Using femtosecond transient absorption spectroscopy rigorously calibrated for the number of absorbed photons, the inner relationship between the microstructures of the quantum dot superlattice and the exciton generation/ dissociation/transfer will be unveiled. The underlying laws and approaches for highly efficient utilization of high energy photons will be elucidated. The scientific problems confronted with multiple exciton generation solar cell assembly, along with the design of device prototypes will be overcome, which will elevate the self-innovation capability of China. This project will promote interdisciplinary developments such as optoelectronic informatics, optoelectronic materials and ultrafast photonics.