Effect of post-thermal annealing on the performance and charge photogeneration dynamics of PffBT4T-2OD/PC71BM solar cells

Research output: Contribution to journalArticle


In this work, we studied influence of post thermal annealing on the performance and charge photogeneration processes of PffBT4T-2OD/PC 71 BM 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.


External organisations
  • Guangzhou University
  • Chongqing University of Arts and Sciences
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Polymer Chemistry
  • Energy Engineering


  • Charge generation, Polymer solar cell, Power conversion efficiency, Thermal annealing
Original languageEnglish
Article number408
Issue number3
Publication statusPublished - 2019
Publication categoryResearch