Effect of Post-Thermal Annealing on the Performance and Charge Photogeneration Dynamics of PffBT4T-2OD/PC71BM Solar Cells

Polymers

Xiaojun Su¹  Arkady Yartsev¹  Xianshao Zou¹  Rong Hu²  Xiaokang Zeng²  Wei Zhang³  Zhifeng Chen³  Jun Peng³  Chengyun Zhang³ 

[1] NanoLund and Division of Chemical Physics, Lund University, Lund 22100, Sweden;Research Institute for New Materials Technology, Chongqing University of Arts and Science, Chongqing 402160, China;School of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006, China;

关键词: polymer solar cell;    power conversion efficiency;    charge generation;    thermal annealing;   

DOI  :  10.3390/polym11030408

来源: DOAJ

【 摘 要 】

In this work, we studied influence of post thermal annealing on the performance and charge photogeneration processes of PffBT4T-2OD/PC71BM solar cells. As-prepared device exhibits a high-power conversion efficiency of 9.5%, much higher than that after thermal annealing. To understand this phenomenon, we studied charge photogeneration processes in these solar cells by means of time resolved spectroscopy. We associate the degradation of solar cell performance with the reduction of exciton dissociation efficiency and with increased bimolecular recombination of photogenerated charges as a result of annealing. We correlate the generation of localized PffBT4T-2OD polarons observed via spectro-electrochemical measurements with enhancement of the bimolecular charge recombination of annealed solar cells.

【 授权许可】

Unknown