Journal
JOURNAL OF PHOTONICS FOR ENERGY
Volume 1, Issue -, Pages -Publisher
SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS
DOI: 10.1117/1.3569105
Keywords
polymer/fullerene solar cell; polymer/polymer solar cell; charge generation; polaron; transient absorption spectroscopy; phase separation
Funding
- JST PRESTO program (Photoenergy and Conversion Systems and Materials for the Next-Generation Solar Cells) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan
- Global COE program (International Center for Integrated Research and Advanced Education in Materials Science) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan
Ask authors/readers for more resources
Currently, polymer/fullerene solar cells have significantly higher power conversion efficiency than polymer/polymer solar cells. In order to address the origin of this wide gap, we measured the transient absorption spectra of polymer/polymer blend films based on poly(3-hexylthiophene) (P3HT) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT), and analyzed the charge generation dynamics in comparison with that of a polymer/fullerene blend film based on P3HT and [6,6]-phenyl-C-61 butyric acid methyl ether (PCBM). In P3HT/PCBM blend films, half of the polarons are generated immediately after pulsed laser excitation at the P3HT absorption band and the other half are generated with a rise constant of similar to 10 ps. The prompt polaron formation is assigned to the charge generation from P3HT singlet excitons located near the P3HT/PCBM interface and the delayed polaron formation to the charge generation after the exciton migration to the P3HT/PCBM interface. In P3HT/F8BT, on the other hand, F8BT singlet excitons observed immediately after the laser excitation decayed in a picosecond and P3HT singlet excitons increased on the same time constant, suggesting efficient energy transfer from F8BT to P3HT. Polymer polarons were generated on a time scale of similar to 40 ps, some of which were observed on a microsecond timescale but the yield was much smaller than that in P3HT/PCBM. We discuss the difference in charge generation dynamics in terms of kinetics and interfacial structures. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3569105]
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available