Abstract
We report a novel combination of organic sensitizer and redox mediator in the electrolyte for dye-sensitized solar cells (DSSCs): a thiophene dye and nitroxide radicals. Nitroxide radicals and their oxidized counterparts of oxoammonium cations show robust reversible redox reactions, thus supporting robust DSSC operations. Moreover, their redox potentials (E 1/2) and thus open-circuit voltages (V OC) can be tuned further by attached functional groups. Optical and electrochemical characterization reveal that these new combinations exhibit enhanced V OC and power conversion efficiencies compared to the existing iodine mediator (I -/I 3 - ) due to the increased V OC. Also, the selection of the sensitizer-redox mediator turns out to be critical in the overall cell performance. Indeed, the typical ruthenium dye loses its light absorption capability when it is operated in conjunction with the nitroxide radicals.
| Original language | English |
|---|---|
| Pages (from-to) | 657-663 |
| Number of pages | 7 |
| Journal | Journal of Solid State Electrochemistry |
| Volume | 16 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2012 |
Bibliographical note
Funding Information:We acknowledge the financial support from the Ministry of Education, Science and Technology, Republic of Korea through the Brain Korea 21 (BK 21) project and the Korea Science and Engineering Foundation grant (WCU program, 31-2008-000-10055-0). And also we acknowledge the National Research Foundation of Korea Grant funded by the Korean Government (MEST) for the financial support (NRT-2010-0029031).
Keywords
- Dye-sensitized solar cell
- Nitroxide
- Open-circuit voltage
- Redox mediator
- Thiophene dye