Song Han, Lin Yu, Zhang Zhengyan, Rao Huashang, Wang Wenran, Fang Yueping, Pan Zhenxiao, Zhong Xinhua
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, People's Republic of China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, People's Republic of China.
J Am Chem Soc. 2021 Mar 31;143(12):4790-4800. doi: 10.1021/jacs.1c01214. Epub 2021 Mar 18.
Low loading is one of the bottlenecks limiting the performance of quantum dot sensitized solar cells (QDSCs). Although previous QD secondary deposition relying on electrostatic interaction can improve QD loading, due to the introduction of new recombination centers, it is not capable of enhancing the photovoltage and fill factor. Herein, without the introduction of new recombination centers, a convenient QD secondary deposition approach is developed by creating new adsorption sites via the formation of a metal oxyhydroxide layer around QD presensitized photoanodes. MgCl solution treated Zn-Cu-In-S-Se (ZCISSe) QD sensitized TiO film electrodes have been chosen as a model device to investigate this secondary deposition approach. The experimental results demonstrate that additional 38% of the QDs are immobilized on the photoanode as a single layer. Due to the increased QD loading and concomitant enhanced light-harvesting capacity and reduced charge recombination, not only photocurrent but also photovoltage and fill factor have been remarkably enhanced. The average PCE of resulted ZCISSe QDSCs is boosted to 15.31% ( = 26.52 mA cm, = 0.802 V, FF = 0.720), from the original 13.54% ( = 24.23 mA cm, = 0.789 V, FF = 0.708). Furthermore, a new certified PCE record of 15.20% has been obtained for liquid-junction QDSCs.
低负载量是限制量子点敏化太阳能电池（QDSCs）性能的瓶颈之一。尽管先前依赖静电相互作用的量子点二次沉积可以提高量子点负载量，但由于引入了新的复合中心，它无法提高光电压和填充因子。在此，在不引入新复合中心的情况下，通过在量子点预敏化光阳极周围形成金属氢氧化物层来创建新的吸附位点，开发了一种简便的量子点二次沉积方法。选择MgCl溶液处理的Zn-Cu-In-S-Se（ZCISSe）量子点敏化TiO薄膜电极作为模型器件来研究这种二次沉积方法。实验结果表明，额外38%的量子点以单层形式固定在光阳极上。由于量子点负载量增加，伴随的光捕获能力增强和电荷复合减少，不仅光电流，而且光电压和填充因子都得到了显著提高。所得ZCISSe QDSCs的平均光电转换效率（PCE）从原来的13.54%（Jsc = 24.23 mA cm，Voc = 0.789 V，FF = 0.708）提高到15.31%（Jsc = 26.52 mA cm，Voc = 0.802 V，FF = 0.720）。此外，液结QDSCs获得了15.20%的新认证PCE记录。
