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