Influence of side groups on the performance of infrared absorbing aza-BODIPY organic solar cells
| Autor: | Koen Vandewal, Johannes Widmer, E. Hieckmann, Melanie Lorenz-Rothe, Christian Koerner, Johannes Benduhn, Daniel Schütze, Donato Spoltore, Frank Ortmann, Sascha Ullbrich, Gianaurelio Cuniberti, Till Jägeler-Hoheisel, Rico Meerheim, Stefan Kraner, Karl Leo, K. Sebastian Radke |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Organic solar cell
Chemistry business.industry Infrared Energy conversion efficiency Surfaces and Interfaces Condensed Matter Physics Photochemistry Polymer solar cell Surfaces Coatings and Films Electronic Optical and Magnetic Materials Electron transfer Materials Chemistry Side chain Optoelectronics Electrical and Electronic Engineering Pendant group business Short circuit |
| Zdroj: | physica status solidi (a). 212:2747-2753 |
| ISSN: | 1862-6300 |
| Popis: | Organic solar cells are a promising technology for a large area conversion of sunlight into electricity. In particular for solar cells based on oligomers (small molecules), efficient donor materials absorbing wavelengths larger than 780 nm are still rare. Here, we investigate three aza-BODIPY dyes absorbing in the infrared. The addition of side groups leads to a red shift of the optical gap from 802 to 818 nm. In optimized devices using these donors in a bulk heterojunction with C-60, we observe a higher charge carrier mobility and a higher power conversion efficiency for the molecules without a methyl or methoxy side group lowering the molecular reorganization energy. Surprisingly, the donor-acceptor blend with the lowest energy loss during the electron transfer to the C-60 yields the highest short circuit current. With increasing size of the attached side chain, the devices exhibit a larger trap density, measured by impedance spectroscopy. Based on the investigation of different blend ratios, we conclude that these traps are mainly present in the donor phase. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text