liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Enhanced photocurrent spectral response in low-bandgap polyfluorene and C70-Derivative-Based Solar Cells
Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
Materials and Surface Chemistry, Chalmers University of Technology, Göteborg, Sweden.
Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, Toledo, Spain.
Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, Toledo, Spain.
Show others and affiliations
2005 (English)In: Advanced Functional Materials, ISSN 1616-301X, Vol. 15, no 10, 1665-1670 p.Article in journal (Refereed) Published
Abstract [en]

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, < 500 nm and 600 <  < 1000 nm. The BTPF70 absorbs light at < 700 nm. A broad photocurrent spectral response in the wavelength range 300 <  < 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.

Place, publisher, year, edition, pages
2005. Vol. 15, no 10, 1665-1670 p.
Keyword [en]
Fullerenes, Polyfluorenes, Solar cells - organic
National Category
Natural Sciences
URN: urn:nbn:se:liu:diva-13889DOI: 10.1002/adfm.200500114OAI: diva2:22131
Available from: 2006-07-07 Created: 2006-07-07 Last updated: 2009-10-05
In thesis
1. Surface Energy Patterning and Optoelectronic Devices Based on Conjugated Polymers
Open this publication in new window or tab >>Surface Energy Patterning and Optoelectronic Devices Based on Conjugated Polymers
2006 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The work presented in this thesis concerns surface energy modification and patterning of the surfaces of conjugated polymers. Goniometry and Wilhelmy Balance techniques were used to evaluate the surface energy or wettability of a polymer’s surface; infrared reflectionabsorption spectroscopy (IRAS) was used to analyse the residuals on the surface as modified by a bare elastomeric stamp poly(dimethylsiloxane) (PDMS). The stamp was found to be capable of modifying a polymer surface. Patterning of a single and/or double layer of conjugated polymers on the surface can be achieved by surface energy controlled dewetting. Modification of a conjugated polymer film can also be carried out when a sample is subjected to electrochemical doping in an aqueous electrolyte. The dynamic surface energy changes during the process were monitored in-situ using the Wilhelmy balance method.

This thesis also concerns studies of conjugated polymer-based optoelectronics, including light-emitting diodes (PLEDs), that generate light by injecting charge into the active polymer layer, and solar cells (PSCs), that create electrical power by absorbing and then converting solar photons into electron/hole pairs. A phosphorescent metal complex was doped into polythiophene to fabricate PLEDs. The energy transfer from the host polymer to the guest phosphorescent metal (iridium and platinum) complex was studied using photoluminescence and electroluminescence measurements performed at room temperature and at liquid nitrogen temperature. PSCs were prepared using low-bandgap polyfluorene copolymers as an electron donor blended with several fullerene derivatives acting as electron acceptors. Energetic match is the main issue affecting efficient charge transfer at the interface between the polymers and the fullerene derivatives, and therefore the performance of the PSCs. Photoluminescence, luminescence quenching and the lowest unoccupied molecular orbital (LUMO) together with the highest occupied molecular orbital (HOMO) of the active materials in the devices were studied. A newly synthesized fullerene, that could match the low-bandgap polymers, was selected and used as electron acceptor in the PSCs. Photovoltaic properties of these PSCs were characterised, demonstrating one of the most efficient polymer:fullerene SCs that generate photocurrent at 1 μm.

Place, publisher, year, edition, pages
Institutionen för fysik, kemi och biologi, 2006
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 996
Surface energy modification, Patterning, Dewetting, Conjugated polymer, plastic solar cell, Low bandgap, Electron acceptors and donors
National Category
Physical Sciences
urn:nbn:se:liu:diva-7065 (URN)91-85497-00-2 (ISBN)
Public defence
2006-03-10, Planck, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
On the day of the defence the status of article number III was Manuscript and article VII was Accepted.Available from: 2006-07-07 Created: 2006-07-07 Last updated: 2009-10-05

Open Access in DiVA

No full text

Other links

Publisher's full textLink to Ph.D. thesis

Search in DiVA

By author/editor
Wang, XiangjunInganäs, Olle
By organisation
Biomolecular and Organic Electronics The Institute of Technology
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 48 hits
ReferencesLink to record
Permanent link

Direct link