Enhanced Photocurrent Spectral Response in Low‐Bandgap Polyfluorene and C70‐Derivative‐Based Solar Cells |
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Authors: | X. Wang,E. Perzon,F. Oswald,F. Langa,S. Admassie,M. R. Andersson,O. Inganä s |
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Abstract: | Plastic solar cells have been fabricated using a low‐bandgap alternating copolymer of fluorene and a donor–acceptor–donor moiety (APFO‐Green1), blended with 3′‐(3,5‐bis‐trifluoromethylphenyl)‐1′‐(4‐nitrophenyl)pyrazolino[70]fullerene (BTPF70) as electron acceptor. The polymer shows optical absorption in two wavelength ranges, λ < 500 nm and 600 < λ < 1000 nm. The BTPF70 absorbs light at λ < 700 nm. A broad photocurrent spectral response in the wavelength range 300 < λ < 1000 nm is obtained in solar cells. A photocurrent density of 3.4 mA cm–2, open‐circuit voltage of 0.58 V, and power‐conversion efficiency of 0.7 % are achieved under illumination of AM1.5 (1000 W m–2) from a solar simulator. Synthesis of BTPF70 is presented. Photoluminescence quenching and electrochemical studies are used to discuss photoinduced charge transfer. |
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Keywords: | Fullerenes Polyfluorenes Solar cells, organic |
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