%0 Journal Article %1 ADFM:ADFM201602162 %A Wang, Kai %A Liang, Ru-Ze %A Wolf, Jannic %A Saleem, Qasim %A Babics, Maxime %A Wucher, Philipp %A Abdelsamie, Maged %A Amassian, Aram %A Hansen, Michael Ryan %A Beaujuge, Pierre M. %D 2016 %J Advanced Functional Materials %K donor organics %N 39 %P 7103--7114 %R 10.1002/adfm.201602162 %T Donor and Acceptor Unit Sequences Influence Material Performance in Benzo1,2-b:4,5-b′dithiophene–6,7-Difluoroquinoxaline Small Molecule Donors for BHJ Solar Cells %U http://dx.doi.org/10.1002/adfm.201602162 %V 26 %X Well-defined small molecule (SM) donors can be used as alternatives to π-conjugated polymers in bulk-heterojunction (BHJ) solar cells with fullerene acceptors (e.g., PC61/71BM). Taking advantage of their synthetic tunability, combinations of various donor and acceptor motifs can lead to a wide range of optical, electronic, and self-assembling properties that, in turn, may impact material performance in BHJ solar cells. In this report, it is shown that changing the sequence of donor and acceptor units along the π-extended backbone of benzo1,2-b:4,5-b′dithiophene–6,7-difluoroquinoxaline SM donors critically impacts (i) molecular packing, (ii) propensity to order and preferential aggregate orientations in thin-films, and (iii) charge transport in BHJ solar cells. In these systems (SM1-3), it is found that 6,7-difluoroquinoxaline (2FQ) motifs directly appended to the central benzo1,2-b:4,5-b′dithiophene (BDT) unit yield a lower-bandgap analogue (SM1) with favorable molecular packing and aggregation patterns in thin films, and optimized BHJ solar cell efficiencies of ≈6.6%. 1H-1H DQ-SQ NMR analyses indicate that SM1 and its counterpart with 2FQ motifs substituted as end-group SM3 possess distinct self-assembly patterns, correlating with the significant charge transport and BHJ device efficiency differences observed for the two analogous SM donors (avg. 6.3% vs 2.0%, respectively).

@article{ADFM:ADFM201602162, abstract = {Well-defined small molecule (SM) donors can be used as alternatives to π-conjugated polymers in bulk-heterojunction (BHJ) solar cells with fullerene acceptors (e.g., PC61/71BM). Taking advantage of their synthetic tunability, combinations of various donor and acceptor motifs can lead to a wide range of optical, electronic, and self-assembling properties that, in turn, may impact material performance in BHJ solar cells. In this report, it is shown that changing the sequence of donor and acceptor units along the π-extended backbone of benzo[1,2-b:4,5-b′]dithiophene–6,7-difluoroquinoxaline SM donors critically impacts (i) molecular packing, (ii) propensity to order and preferential aggregate orientations in thin-films, and (iii) charge transport in BHJ solar cells. In these systems (SM1-3), it is found that 6,7-difluoroquinoxaline ([2F]Q) motifs directly appended to the central benzo[1,2-b:4,5-b′]dithiophene (BDT) unit yield a lower-bandgap analogue (SM1) with favorable molecular packing and aggregation patterns in thin films, and optimized BHJ solar cell efficiencies of ≈6.6%. 1H-1H DQ-SQ NMR analyses indicate that SM1 and its counterpart with [2F]Q motifs substituted as end-group SM3 possess distinct self-assembly patterns, correlating with the significant charge transport and BHJ device efficiency differences observed for the two analogous SM donors (avg. 6.3% vs 2.0%, respectively).}, added-at = {2016-10-18T10:01:44.000+0200}, author = {Wang, Kai and Liang, Ru-Ze and Wolf, Jannic and Saleem, Qasim and Babics, Maxime and Wucher, Philipp and Abdelsamie, Maged and Amassian, Aram and Hansen, Michael Ryan and Beaujuge, Pierre M.}, biburl = {https://www.bibsonomy.org/bibtex/29c2c8e6c3ca49b821a1a9b1b453e727a/cgoehler}, description = {new donor material synthesized and tested}, doi = {10.1002/adfm.201602162}, interhash = {97416a4c2d557c48bd4ba638fdd971a5}, intrahash = {9c2c8e6c3ca49b821a1a9b1b453e727a}, issn = {1616-3028}, journal = {Advanced Functional Materials}, keywords = {donor organics}, number = 39, pages = {7103--7114}, timestamp = {2016-10-18T10:01:44.000+0200}, title = {Donor and Acceptor Unit Sequences Influence Material Performance in Benzo[1,2-b:4,5-b′]dithiophene–6,7-Difluoroquinoxaline Small Molecule Donors for BHJ Solar Cells}, url = {http://dx.doi.org/10.1002/adfm.201602162}, volume = 26, year = 2016 }