基于三维导电网络纳米结构电极材料的高效量子点敏化太阳能电池的研究

Thanks to the high theoretical power conversion efficiency (PCE) and the multiple exciton generation effect and the bandgap engineerable to match full solar spectrum of quantum dots (QD), quantum-dots-sensitized solar cells (QDSCs) have recently received much attention and been considered as an alternative to new generation photovoltaic devices. However, ~7% of the state-of-art PCE of QDSCs still lags far behind other solar cells. Aiming at enhancing PCE of QDSC, this project will focus on the design and development of new three-dimensional (3D) conductive nanostructure network for the preparation of photoanode and counter electrodes, new nanostructured QDs with broader absorption, and the assembly methods for high-efficiently loading quantum dots on photoanodes. The high-performance photoanodes will be fabricated by efficiently loading the developed QDs on the developed 3D electrodes. The high-performance counter electrodes will be prepared by growing highly-active nanocatalysts for electrolyte reaction such as Cu2S nanocrystals on the developed 3D electrodes. The 3D conductive electrode network will not only accelerate the carrier transport at both anodes and counter electrodes, enhance the loading of QDs on anodes and active nanocrystals on counter electrodes, decrease the series resistance of the device, but also facilitate the mass transfer of electrolyte. The project will also develop the methods for the surface modification of QD and photoanodes, and the methods for optimizing the interface between 3D electrodes and oxide nanocrystals at photoanode, the interface between 3D electrodes and nanocatalysts at counter electrode. Finally, it is expected to achieve QDSCs with high PCE by enhancing short-circuit current, open-circuit voltage and fill factor of a cell with the above-mentioned new photoanodes and counter electrodes as well as the developed techniques of interface modification.

量子点敏化太阳能电池因其高达44%的理论转换效率和多激子产生效应而成为备受关注和极具发展潜力的新型太阳能电池之一，但其目前最高约7%的转化效率仍远落后于其它类型太阳能电池。本项目拟从设计构建具有三维导电网络纳米结构的电极材料出发，通过设计构建基于透明导电三维网络纳米结构电极与氧化物半导体的光阳极电极材料，合成宽光谱吸收的高效量子点敏化剂，开发量子点的高效负载技术来构筑高性能光阳极；构建基于三维导电网络纳米结构电极与高催化活性纳晶复合的高性能对电极。利用三维导电网络结构电极提高载流子的分向输运能力，降低电池的串联电阻，加速电解质的传质；通过新型宽光谱吸收量子点的设计合成与高效负载，增加光的吸收和载流子分离效率；通过量子点和光阳极的表面修饰，以及各界面结构的优化降低载流子的复合几率；以期有效地提高量子点敏化太阳能电池的短路电流、开路电压和填充因子，最终实现高转换效率的量子点敏化太阳能电池。

项目组针对量子点敏化太阳能电池研究中的关键科学问题，主要围绕三维导电纳米结构电极材料与量子点敏化太阳能电池器件开展研究工作。设计构筑了系列具有三维导电网络结构的纳米结构化光阳极材料与对电极材料。研究表明三维导电网络结构电极可以显著提高载流子的分向输运能力，降低电池的串联电阻与电荷传输电阻，并且加速电解质的传质。开发了系列具有宽光谱吸收特点的、不含高毒性重金属的新型绿色、高效量子点材料，并且发展了量子点高效负载的新方法。深入研究了载流子传输与复合动力学，发展了系列界面修饰与调控新策略，改善了载流子在界面的复合。获得了转化效率可达11.49%的量子点敏化太阳能电池器件，全面实现了项目研究目标。此外，项目组还探索研究了全固态量子点太阳能电池和钙钛矿太阳能电池，并且首次报道了新型GeSe薄膜太阳能电池。.通过项目的实施，已经发表学术论文48篇，其中影响因子10以上的论文28篇，包括9篇JACS和2篇Angew. Chem.等。14研究论文入选ESI热点和/或高被引研究论文。申请中国发明专利 11项，已授权4项。培养博士研究生6名。项目组成员薛丁江助理研究员晋升研究员，并获基金委优秀青年基金资助。受邀参加MRS年会等学术会议并做邀请报告8次。