Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai 200237 , China.
ACS Appl Mater Interfaces. 2019 Feb 20;11(7):6927-6936. doi: 10.1021/acsami.8b18033. Epub 2019 Feb 6.
The balance between band structure, composition, and defect is essential for improving the optoelectronic properties of ternary and quaternary quantum dots and the corresponding photovoltaic performance. In this work, ascorbic acid (AA) as capping ligand is introduced into the reaction system to prepare green Zn-Cu-In-Se (ZCISe) quantum dots. Results show that the addition of AA can increase the Zn content while decrease the In content, resulting in enlarged band gap, high conduction band energy level, and suppressed charge recombination. When AA/Cu ratio is 1, the quantum dots possess the largest band gap of 1.49 eV and the assembled quantum dot-sensitized solar cells exhibit superior photovoltaic performance with ∼17% increment mainly contributed by the dramatically increased current density. The new record efficiencies of 10.44 and 13.85% are obtained from the ZCISe cells assembled with brass and titanium mesh-based counter electrodes, respectively.
在改善三元和四元量子点的光电性能和相应光伏性能方面，平衡能带结构、组成和缺陷至关重要。在这项工作中，我们引入抗坏血酸（AA）作为配体来制备绿色的 Zn-Cu-In-Se（ZCISe）量子点。结果表明，AA 的加入可以增加 Zn 的含量，同时降低 In 的含量，从而导致带隙增大、导带能级升高、抑制电荷复合。当 AA/Cu 比为 1 时，量子点具有最大的带隙 1.49eV，组装的量子点敏化太阳能电池表现出优异的光伏性能，电流密度显著增加，约为 17%。使用黄铜和钛网作为对电极组装的 ZCISe 电池分别获得了 10.44%和 13.85%的新纪录效率。
