Journal article
Large-area photovoltaics based on low band gap copolymers of thiophene and benzothiadiazole or benzo-bis(thiadiazole)
Risø National Laboratory for Sustainable Energy, Technical University of Denmark1
Polymers for Energy Technology, Polymer Department, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Polymer Department, Risø National Laboratory for Sustainable Energy, Technical University of Denmark3
Large-area solar cells (active area = 3 and 10cm(2)) were prepared with low band gap polymers based on thiophene and benzothiadiazole (1) or thiophene and benzo-bis(thiadiazole) (2). The band gaps of the polymers were 1.65 and 0.67 eV, respectively. The best photovoltaic performance was obtained for the device ITO/PEDOT/1:PCBM (1:2)/Al with an active area of 3 cm(2).
The efficiency of the device was 0.62%. This is a high efficiency for a low band gap polymer in a large-area organic solar cell and thus polymer I is a very promising material for organic solar cells. The devices based on 2 were found to give poor devices when employed in bulk heterojunctions with PCBM.
This was linked to a poor alignment of the energy levels in 2 with that of the electrodes and PCBM, showing that the requirement for a control of the positions of the energy levels becomes increasingly important as the band gap decreases. (c) 2007 Elsevier B.V. All rights reserved.
| Language: | English |
|---|---|
| Year: | 2007 |
| Pages: | 1019-1025 |
| ISSN: | 18793398 and 09270248 |
| Types: | Journal article |
| DOI: | 10.1016/j.solmat.2007.01.013 |
| ORCIDs: | Bundgaard, Eva and Krebs, Frederik C |
Large-area organic photovoltaic devices Low band gap polymers
