| Record |
| Author |
Ben Dkhil, S.; Pfannmöller, M.; Ata, I.; Duche, D.; Gaceur, M.; Koganezawa, T.; Yoshimoto, N.; Simon, J.-J.; Escoubas, L.; Videlot-Ackermann, C.; Margeat, O.; Bals, S.; Bauerle, P.; Ackermann, J. |
| Title |
Time evolution studies of dithieno[3,2-b:2 ',3 '-d] pyrrole-based A-D-A oligothiophene bulk heterojunctions during solvent vapor annealing towards optimization of photocurrent generation |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
| Volume |
5 |
Issue |
5 |
Pages |
1005-1013 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Solvent vapor annealing (SVA) is one of the main techniques to improve the morphology of bulk heterojunction solar cells using oligomeric donors. In this report, we study time evolution of nanoscale morphological changes in bulk heterojunctions based on a well-studied dithienopyrrole-based A-D-A oligothiophene (dithieno[3,2-b: 2',3'-d] pyrrole named here 1) blended with [6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM) to increase photocurrent density by combining scanning transmission electron microscopy and low-energy-loss spectroscopy. Our results show that SVA transforms the morphology of 1 : PC71BM blends by a three-stage mechanism: highly intermixed phases evolve into nanostructured bilayers that correspond to an optimal blend morphology. Additional SVA leads to completely phaseseparated micrometer-sized domains. Optical spacers were used to increase light absorption inside optimized 1 : PC71BM blends leading to solar cells of 7.74% efficiency but a moderate photocurrent density of 12.3 mA cm (-2). Quantum efficiency analyses reveal that photocurrent density is mainly limited by losses inside the donor phase. Indeed, optimized 1 : PC71BM blends consist of large donor-enriched domains not optimal for exciton to photocurrent conversion. Shorter SVA times lead to smaller domains; however they are embedded in large mixed phases suggesting that introduction of stronger molecular packing may help us to better balance phase separation and domain size enabling more efficient bulk heterojunction solar cells. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Cambridge |
Editor |
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| Language |
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Wos |
000394430800018 |
Publication Date |
2016-11-30 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue  |
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Edition |
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| ISSN |
2050-7488; 2050-7496 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
8.867 |
Times cited |
19 |
Open Access |
Not_Open_Access |
| Notes |
; We acknowledge financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (Grant number: F1110019V/201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7, Grant number: 287594). The synchrotron radiation experiments were performed at BL19B2 in SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2016A1568). We further acknowledge financial support via ERC Starting Grant Colouratoms (335078). ; |
Approved |
Most recent IF: 8.867 |
| Call Number |
UA @ lucian @ c:irua:142602UA @ admin @ c:irua:142602 |
Serial |
4695 |
| Permanent link to this record |
