%0 Journal Article %1 ADFM:ADFM201601134 %A Wang, Tonghui %A Ravva, Mahesh Kumar %A Brédas, Jean-Luc %D 2016 %J Advanced Functional Materials %K DFT organic theory %P n/a--n/a %R 10.1002/adfm.201601134 %T Impact of the Nature of the Side-Chains on the Polymer-Fullerene Packing in the Mixed Regions of Bulk Heterojunction Solar Cells %U http://dx.doi.org/10.1002/adfm.201601134 %X Polymer-fullerene packing in mixed regions of a bulk heterojunction solar cell is expected to play a major role in exciton-dissociation, charge-separation, and charge-recombination processes. Here, molecular dynamics simulations are combined with density functional theory calculations to examine the impact of nature and location of polymer side-chains on the polymer-fullerene packing in mixed regions. The focus is on poly-benzo1,2-b:4,5-b′dithiophene-thieno3,4-cpyrrole-4,6-dione (PBDTTPD) as electron-donating material and 6,6-phenyl-C61-butyric acid methyl ester (PC61BM) as electron-accepting material. Three polymer side-chain patterns are considered: i) linear side-chains on both benzodithiophene (BDT) and thienopyrroledione (TPD) moieties; ii) two linear side-chains on BDT and a branched side-chain on TPD; and iii) two branched side-chains on BDT and a linear side-chain on TPD. Increasing the number of branched side-chains is found to decrease the polymer packing density and thereby to enhance PBDTTPD–PC61 BM mixing. The nature and location of side-chains are found to play a determining role in the probability of finding PC61BM molecules close to either BDT or TPD. The electronic couplings relevant for the exciton-dissociation and charge-recombination processes are also evaluated. Overall, the findings are consistent with the experimental evolution of the PBDTTPD–PC61BM solar-cell performance as a function of side-chain patterns.

@article{ADFM:ADFM201601134, abstract = {Polymer-fullerene packing in mixed regions of a bulk heterojunction solar cell is expected to play a major role in exciton-dissociation, charge-separation, and charge-recombination processes. Here, molecular dynamics simulations are combined with density functional theory calculations to examine the impact of nature and location of polymer side-chains on the polymer-fullerene packing in mixed regions. The focus is on poly-benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c]pyrrole-4,6-dione (PBDTTPD) as electron-donating material and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as electron-accepting material. Three polymer side-chain patterns are considered: i) linear side-chains on both benzodithiophene (BDT) and thienopyrroledione (TPD) moieties; ii) two linear side-chains on BDT and a branched side-chain on TPD; and iii) two branched side-chains on BDT and a linear side-chain on TPD. Increasing the number of branched side-chains is found to decrease the polymer packing density and thereby to enhance PBDTTPD–PC61 BM mixing. The nature and location of side-chains are found to play a determining role in the probability of finding PC61BM molecules close to either BDT or TPD. The electronic couplings relevant for the exciton-dissociation and charge-recombination processes are also evaluated. Overall, the findings are consistent with the experimental evolution of the PBDTTPD–PC61BM solar-cell performance as a function of side-chain patterns.}, added-at = {2016-08-01T11:23:25.000+0200}, author = {Wang, Tonghui and Ravva, Mahesh Kumar and Brédas, Jean-Luc}, biburl = {https://www.bibsonomy.org/bibtex/20e3913af0c525408915f8b1c1846b1d2/bretschneider_m}, doi = {10.1002/adfm.201601134}, interhash = {1940b049ecd34318d3f919fe3962bf8b}, intrahash = {0e3913af0c525408915f8b1c1846b1d2}, issn = {1616-3028}, journal = {Advanced Functional Materials}, keywords = {DFT organic theory}, pages = {n/a--n/a}, timestamp = {2016-08-01T11:23:25.000+0200}, title = {Impact of the Nature of the Side-Chains on the Polymer-Fullerene Packing in the Mixed Regions of Bulk Heterojunction Solar Cells}, url = {http://dx.doi.org/10.1002/adfm.201601134}, year = 2016 }