Side-chain tunability of furan-containing low-band-gap polymers provides control of structural order in efficient solar cells
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
KAUST Solar Center (KSC)
Chemical Science Program
Permanent link to this recordhttp://hdl.handle.net/10754/562083
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AbstractThe solution-processability of conjugated polymers in organic solvents has classically been achieved by modulating the size and branching of alkyl substituents appended to the backbone. However, these substituents impact structural order and charge transport properties in thin-film devices. As a result, a trade-off must be found between material solubility and insulating alkyl content. It was recently shown that the substitution of furan for thiophene in the backbone of the polymer PDPP2FT significantly improves polymer solubility, allowing for the use of shorter branched side chains while maintaining high device efficiency. In this report, we use PDPP2FT to demonstrate that linear alkyl side chains can be used to promote thin-film nanostructural order. In particular, linear side chains are shown to shorten π-π stacking distances between backbones and increase the correlation lengths of both π-π stacking and lamellar spacing, leading to a substantial increase in the efficiency of bulk heterojunction solar cells. © 2011 American Chemical Society.
SponsorsThis work was supported in part by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, the Center for Advanced Molecular Photovoltaics (CAMP) under Award No. KUS-C1-015-21, supported by King Abdullah University of Science and Technology (KAUST), and the Frechet "various gifts" fund for the support of research in new materials. Portions of this research were carried out at the Stanford Synchrotron Radiation Lightsource user facility, operated on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.
PublisherAmerican Chemical Society (ACS)