Song Han, Lin Yu, Zhou Mengsi, Rao Huashang, Pan Zhenxiao, Zhong Xinhua
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou, 510642, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
Angew Chem Int Ed Engl. 2021 Mar 8;60(11):6137-6144. doi: 10.1002/anie.202014723. Epub 2021 Jan 28.
The photoelectronic properties of quantum dots (QDs) have a critical impact on the performance of quantum-dot-sensitized solar cells (QDSCs). Currently, I-III-VI group QDs have become the mainstream light-harvesting materials in high-performance QDSCs. However, it is still a great challenge to achieve satisfactory efficiency for light-harvesting, charge extraction, and charge collection simultaneously in QDSCs. We design and prepare Zn Cu In S Se (ZCISSe) quinary alloyed QDs by cation/anion co-alloying strategy. The critical photoelectronic properties of target QDs, including band gap, conduction band energy level, and density of defect trap states, can be conveniently tailored. Experimental results demonstrate that the ZCISSe quinary alloyed QDs can achieve an ideal balance among light-harvesting, photogenerated electron extraction, and charge-collection efficiencies in QDSCs compared to its single anion or cation quaternary alloyed QD counterparts. Consequently, the quinary alloyed QDs boost the certified efficiency of QDSCs to 14.4 %, which is a new efficiency record for liquid-junction QD solar cells.
量子点（QDs）的光电特性对量子点敏化太阳能电池（QDSCs）的性能有着至关重要的影响。目前，I-III-VI族量子点已成为高性能量子点敏化太阳能电池中的主流光捕获材料。然而，要在量子点敏化太阳能电池中同时实现令人满意的光捕获、电荷提取和电荷收集效率，仍然是一个巨大的挑战。我们通过阳离子/阴离子共合金化策略设计并制备了Zn Cu In S Se（ZCISSe）五元合金量子点。目标量子点的关键光电特性，包括带隙、导带能级和缺陷陷阱态密度，都可以方便地进行调整。实验结果表明，与单阴离子或阳离子四元合金量子点相比，ZCISSe五元合金量子点在量子点敏化太阳能电池的光捕获、光生电子提取和电荷收集效率之间能够实现理想的平衡。因此，五元合金量子点将量子点敏化太阳能电池的认证效率提高到了14.4%，这是液结量子点太阳能电池的新效率记录。
