Journal
CHEMISTRY OF MATERIALS
Volume 26, Issue 2, Pages 1234-1242Publisher
AMER CHEMICAL SOC
DOI: 10.1021/cm4035903
Keywords
-
Funding
- Center for Advanced Soft Electronics under Global Frontier Research Program of the Ministry of Education, Science and Technology [2012055225]
- New and Renewable Energy Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP)
- Ministry of Knowledge Economy (MKE) [20113010010030]
- NRF
- Korean Government (NRF-Global Ph.D. Fellowship Program)
Ask authors/readers for more resources
We designed and synthetized a new poly{4,8-bis((2-ethylhexyl)thieno[3,2-b]thiophene)-benzo[1,2-b:4,5-b']dithiophene-alt-2-ethylhexyl-4,6-di- bromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate} (PTTBDT-FTT) comprising bis(2-ethylhexylthieno[3,2-b]thiophenylbenzo[1,2-b:4,5-b']dithiophene (TTBDT) and 2-ethylhexyl 3-fluorothieno[3,4-b]thiophene-2-carboxylate (FTT). The optical bandgap of PTTBDT-FTT was 1.55 eV. The energy levels of the highest occupied and lowest unoccupied molecular orbitals of PTTBDT-FTT were -5.31 and -3.73 eV, respectively. Two-dimensional grazing-incidence X-ray scattering measurements showed that the film's PTTBDT-FTT chains are predominantly arranged with a face-on orientation with respect to the substrate, with strong pi-pi stacking. An organic thin-film transistor fabricated using PTTBDT-FTT as the active semiconductor showed high hole mobility of 2.1 x 10(-2) cm(2)/(V.s). Single-junction bulk heterojunction photovoltaic cells with the configuration ITO/PEDOT:PSS/PTTBDT-FTT:PC71BM/Ca/Al were fabricated, which showed a maximum power conversion efficiency (PCE) of 7.44%. Inverted photovoltaic cells with the structure ITO/PEIE/PTTBDT-FTT:PC71/BM/MoO3/Ag were also fabricated, with a maximum PCE of 7.71%. A tandem photovoltaic device comprising the inverted PTTBDT-FTT:PC71BM cell and a P3HT:ICBA-based cell as the top and bottom cell components, respectively, showed a maximum PCE of 8.66%. This work demonstrated that the newly developed PTTBDT-FTT polymer was very promising for applications in both single and tandem solar cells. Furthermore, this work highlighted the fact that an extended pi-system in the electron-donor moiety in low bandgap polymers is crucial for improving polymer solar cells.
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