基于新型纳米网络结构电极的设计、可控合成及量子点敏化太阳能电池性能研究

There is an urgent global need for alternative, renewable energy sources for both environmental and economic reasons. One extremely appealing source of energy is the sun, which continuously sends enormous quantities of light energy to the surface of the earth. The popular dye-sensitized solar cells (DSSCs) operate in this regenerative photodevices, as do the liquid junction quantum dot-sensitized solar cells (QDSSCs). However, the performance QDSSCs is much less than expectations. Here, we choose the cadmium sulfide nanobelts/lead sulfide quantum dots (CdS/PbS) crosslink nanostructures as photoanode and the one dimension carbon-based nanomaterials as counter electrode to increase QDSSCs’ efficiency. PbS colloidal quantum dots (CQDs) solar cells possess the advantages of absorption into the infrared, solution processing, and multiple exciton generation, making them very competitive as a low-cost photovoltaic alternative. The effective electron mobility of CdS could promote electron transport. CdS nanobelts with high surface area which could significantly increase the loading amount of PbS QDs. The built-in internal field which generated from the p-n junctions between PbS quantum dots and CdS nanobelts can separate the excitons efficiently. Carbon-based nanomaterials with high surface area and the hetero-atoms dopants and surface modification could significantly enhance the catalysis performance which make carbon-based nanomaterials as outstanding counter electrode materials for QDSSCs. This project expect to detect the effect of barrier of CdS nanobelts for the procedure of carrier transport, understand the relations between the concentration of dopants and the catalytic activity, and offer new possibilities for the innovation of nanostructures to optimize the QDSSCs’ performance.

本项目针对目前量子点敏化太阳能电池光电转换效率远低于理论预期的问题，围绕探索提高量子点光吸收效率、光生激子分离效率、光生载流子传输效率、载流子收集效率的新途径，提出采用CdS纳米带/PbS量子点新型网络结构阳极和一维碳基纳米材料网络结构对电极。利用CdS纳米带大比表面积提高PbS量子点负载量，改善光阳极的光吸收效率；利用PbS/CdS形成的p-n结内建电场实现激子的有效分离；利用CdS纳米带的高电子迁移率实现电子的有效传输；利用掺杂碳基对电极网络结构实现对电解质中空穴的有效收集。重点开展：新型纳米网络结构电极的设计及可控制备研究；载流子输运过程研究；性能评估及原理型器件构筑研究。揭示网络结构阳极中纳米带间的接触势垒对载流子输运过程的影响规律，以及一维碳基对电极中杂原子电子结构与浓度对电解质还原反应催化活性的影响规律等科学问题，为发展新型高效量子点敏化太阳能电池电极材料奠定理论和实验基础。

本项目针对目前量子点敏化太阳能电池光电转换效率远低于理论预期的问题，围绕探索提高量子点光吸收效率、光生激子分离效率、光生载流子传输效率、载流子收集效率的新途径，提出采用PbS纳米带新型网络结构阳极，负载CdS，MoS2及WS2纳米颗粒/量子点和一维碳基纳米材料网络结构对电极。利用PbS纳米带大比表面积提高活性纳米材料或量子点的负载量，改善光阳极的光吸收效率；利用PbS/CdS形成的pn结内建电场实现激子的有效分离；利用PbS纳米带的高电子迁移率实现电子的有效传输；利用掺杂碳基对电极网络结构实现对电解质中空穴的有效收集。重点开展：新型纳米网络结构电极的设计及可控制备研究；载流子输运过程研究；性能评估及原理型器件构筑研究。揭示网络结构阳极中纳米带间的接触势垒对载流子输运过程的影响规律，以及碳基对电极中杂原子电子结构与浓度对电解质还原反应催化活性的影响规律等科学问题，为发展新型高效量子点敏化太阳能电池电极材料奠定理论和实验基础。