多组分量子点共敏化光阳极研究

The low-cost solar cell technology represented by quantum dot sensitized solar cell (QDSC) is an effective route to solve the social problems such as energy and environment. The photoelectronic conversion efficiency of QDSCs are limited by the properties of the single component quantum dots that unusually cannot possess a wide light absorption ability, high conduction band position and high absorption intensity simultaneously. Based on our deep comprehension of the nature about QDSC structures and charge transport, quantum dots cosensitized photoanodes will be introduced into QDSCs in this project in view of the tunablity of their optoelectronic properties via controlling their composition. The different quantum dots with complementary properties on light absorption and photoelectron injection will be assembled on porous TiO2 films via surface ligands induced self-assembly to prepare cosensitized photoanodes. The essential issues, that is, the kinetics of the transportation and recombination of photo-generated electrons at heterogeneous interface; the intrinsic relationship among the constitution, structure, and photoelectric properties of cosensitized photoanodes; and the mechanism of the capture and utilization of solar energy on cosensitized photoanodes, will be investigated in detail. Eventually, new methods of obtaining the high photoelectrical conversion efficiency of QDSCs would be theoretically proposed and experimentally verified. With the implementation of this preject, the conversion efficiency of QDSC will be uplifted to over 12%. The investigation results of this work will provide theoretical basis and technical support for commercial application of QDSCs.

以量子点敏化太阳电池（QDSC）为代表的低成本太阳电池技术是解决能源和环境等社会问题的一种有效途径。目前普遍采用的单一组分量子点敏化剂在宽光谱吸收、高导带能位及高吸光强度间存在顾此失彼的矛盾，严重制约了QDSC光电转换效率的提高。基于量子点间的能带耦合能够有效调控电子结构这一思想，结合我们对QDSC结构-电荷界面传输机制的多年探索，本项目拟将多组分量子点共敏化光阳极引入QDSC。课题采用表面配体诱导自组装策略，将对光吸收及光电子注入具有互补效应的预合成量子点负载在介孔光阳极膜内以制备多组分共敏化光阳极。系统研究电荷界面传输及复合动力学，探索共敏化光阳极组分-结构-光电性能之间的内在联系，揭示基于量子点单元间协同效应的共敏化光阳极对太阳光捕获利用的可控调节机制。建立获得高光电转换效率的新方法，实现研制的QDSC效率大于12%。研究成果将为QDSC的商业化应用提供理论基础和技术支撑。

量子点敏化太阳能电池(QDSCs)因其制备工艺简单、成本低且理论转换效率高等优势成为了最具潜力的第三代太阳能电池之一。然而QDSCs实际光电转换效率仍与传统硅基电池相差甚远，且远低于其理论值。针对单一组分量子点敏化剂在宽光谱吸收、高导带能位及高吸光强度间的存在顾此失彼所制约的QDSCs光电效率提高这一难题，本项目首先合成性能匹配的低缺陷密度的胶体量子点及钙钛矿量子点。在此基础上，基于界面工程策略，通过对量子点及基底材料的表界面修饰，实现了性能互补的预合成胶体量子点在介孔膜内的可控且高密度负载。同时，基于增加催化活性位点的思路，设计制备了系列金属框架材料衍生的高催化活性碳材料，并将其用于对电极制备，以提高对电极催化活性。通过对该类太阳能电池器件性能的综合优化，最终实现超13%的光电转换效率，刷新同期该类电池的效率记录。