| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1267145 | Organic Electronics | 2016 | 6 Pages |
•Formic acid (FA) was used as a novel additive in PTB7:PC71BM based organic solar cells.•The best PCE of 9.04% with 24.6% improvement was obtained with 6 vol% FA doping.•Enhanced PCE was attributed to the increase of exciton generation and enhanced charge-carrier mobility of the devices.
Formic acid (FA) was used as a novel additive in bulk heterojunction (BHJ) solar cells, which contains blends of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl]] (PTB7) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The effect of FA on the performance of PTB7:PC71BM based BHJ solar cells is investigated. By the incorporation of FA, the device with the ratio of 6 vol % shows the best power conversion efficiency (PCE) of 9.04%, along with the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) being 24.11 mA/cm2, 0.72 V, and 52.11%, respectively. Experimental results suggest that FA has a strong influence on charge carrier dynamics with a significant increase in Jsc by ∼65% and the dramatically enhanced PCE is mainly due to the increase of absorption and exciton generation of the active layers and the improved charge-carrier mobility of the devices.
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