| 1. |
- Inganäs, Olle, et al.
(författare)
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Low bandgap alternating polyfluorene copolymers in plastic photodiodes and solar cells
- 2004
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Ingår i: Applied Physics A. - : Springer Science and Business Media LLC. - 0947-8396 .- 1432-0630. ; 79:1, s. 31-35
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Tidskriftsartikel (refereegranskat)abstract
- We report a comparative study of plastic photodiodes using four different copolymers of fluorene, with a variation of alkyl side chain length and chemical structure. Photodiode materials are formed by blending the polymers with a fullerene derivative and spincoating the blend solution. A photovoltage of 1 V is obtained in devices, where the anode is a doped polymer and the cathode is LiF/Al. Monochromatic quantum efficiencies are better than 40% over most of the absorption range, and under solar light AM 1.5 simulation, we reach energy efficiencies beyond 2%. The high fill factors obtained in some of the devices indicate that these are of interest for more elaborate optimisation. Reasons for the benign electrical transport are discussed. © Springer-Verlag 2004.
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| 2. |
- Svensson, M., et al.
(författare)
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High-performance polymer solar cells of an alternating polyfluorene copolymer and a fullerene derivative
- 2003
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 15:12, s. 988-991
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Tidskriftsartikel (refereegranskat)abstract
- High-performance polymer solar cells of an alternating polyfluorene copolymer, PFDTBT, and a fullerene derivative were studied. It was shown that PFDTBT is a promising candidate for obtaining high energy conversion efficiency when combined with a suitable electron acceptor. Results showed that high-performance solar cells with extended spectral coverage and increased open-circuit voltage could be prepared from composites prepared from electron acceptor.
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| 3. |
- Svensson, M., et al.
(författare)
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Synthesis and properties of alternating polyfluorene copolymers with redshifted absorption for use in solar cells
- 2003
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Ingår i: Synthetic metals. - : Elsevier. - 0379-6779 .- 1879-3290. ; 135-136, s. 137-138
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Tidskriftsartikel (refereegranskat)abstract
- Three fluorene based alternating copolymers with redshifted absorption were synthesized and used as the active layer in photodiodes. The polymers are soluble in common solvents. The photodiodes cover a large part of the solar spectrum with high external quantum efficiency and we reach 2.4% power conversion efficiency for the best device in this study.
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| 4. |
- Yohannes, T., et al.
(författare)
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Polyfluorene copolymer based bulk heterojunction solar cells
- 2004
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Ingår i: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 449:1-2, s. 152-157
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Tidskriftsartikel (refereegranskat)abstract
- Bulk heterojunction solar cells based on blends of photoactive layers of polyfluorene copolymer Poly((2,7-(9-(2'-ethylhexyl)-9-hexyl-fluorene)-alt-5,5-(4', 7'-di-2-thienyl-2',1',3'-benzothiadiazole))-co-(2, 7-(9-(2'-ethylhexyl)-9-hexyl-fluorene)-alt-2,5-thiophene)) (LBPF3) acting as electron donor, and [6,6]-phenyl-C61-butyric acid methylester (PCBM), acting as electron acceptor, were constructed and studied. The power conversion efficiency for a 1:4 (by weight) blend of LBPF3:PCBM under simulated solar light illumination having light intensity of 100 mW/cm2 was 1.7%, and 9.2% under monochromatic (565 nm) light illumination with light intensity of 0.145 mW/cm2. The maximum external quantum efficiency (incident photons to converted electrons) for this device was found to be above 40% from 400 to 560 nm. The effects of blend composition and film thickness on the photovoltaic parameters were also studied. The incident light intensity dependence of the short circuit current showed a linear relationship. © 2003 Elsevier B.V. All rights reserved.
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| 5. |
- Zhang, Fengling, et al.
(författare)
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Influence of buffer layers on the performance of polymer solar cells
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 84:19, s. 3906-3908
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Tidskriftsartikel (refereegranskat)abstract
- The study of the influence of different anode buffer layers on the performance of solar cells based on blends of polyfluorene copolymers, acting as electron donor, and [6,6]-phenyl-C61-butyric acid methylester (PCBM), acting as electron acceptor was presented. The construction of buffer later was done from different forms of poly(3, 4-ethylenedioxythiophene) poly-(styrenesulfonate) (PEDOT-PSS). Variations in open-circuit voltage, short-circuit current and fill factor were also observed. The anode buffer layer influences the photovoltage of polymer solar cells by controlling the conditions for charge injection at the anode.
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| 6. |
- Zhang, Fengling, et al.
(författare)
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Soluble polythiophenes with pendant fullerene groups as double cable materials for photodiodes
- 2001
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Ingår i: Advanced Materials. - 0935-9648 .- 1521-4095. ; 13:24, s. 1871-
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Tidskriftsartikel (refereegranskat)abstract
- A novel "double cable" material for photodiodes, containing both electron- and hole-transporting functional groups, is obtained by co-polymerization of thiophenes that bear a covalently linker-bound fullerene (see Figure). Even at 14% of fullerene substitution, the order of the main polythiophene chain is not seriously disturbed.
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