题目：Insights into efficiency deviation from current-mismatch for tandem photovoltaics

作者：Yining Bao ^a,b, Tianshu Ma ^a,b, Zhenhai Ai ^a,b, Yuqi Zhang ^a,b, Luolei Shi ^a,b, Linling Qin ^a,b, Zhenhai Yang ^a,b,*, Guoyang Cao ^a,b,*, Changlei Wang ^a,b, Xiaofeng Li ^a,b,*

单位：

^a School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006,China

^b Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China

摘要：For tandem solar cells (TSCs), the highest efficiency is generally believed to occur when the top and bottom sub-cells obtain an identical photocurrent, i.e., the current-match condition. However, the real situation is that there is a slight deviation from the matching point, which is an interesting phenomenon, but lacks a clear explanation. Here, we report a coupled photoelectric investigation on the intrinsic mechanisms within TSCs under various current configurations. Taking an all-perovskite TSC as an example, we find that the efficiency deviation orig-inates from the current reduction and fill factor (FF) compensation; moreover, the optimal efficiency depends primarily on the sub-cells with higher FF. Our analysis further reveals that the higher FF and efficiency are achieved under current-mismatch condition due to the differentiated voltage assignments among the sub-cells, i.e., the sub-cells with higher currents require larger voltages in order to effectively recombine the surplus cur-rents. We also find that the impact of sub-cell leakage on TSC performance can be partially alleviated by increasing the current of the affected sub-cell. Such an optoelectronic insight offers a valuable guidance for designing high-efficiency TSCs.

影响因子：17.6

链接：https://doi.org/10.1016/j.nanoen.2023.109165