| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 79751 | Solar Energy Materials and Solar Cells | 2011 | 5 Pages |
We report the enhanced performance and stability of polymer solar cells based on regioregular poly(3-hexylthiophene) (P3HT) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend using lithium benzoate (C6H5COOLi) as cathode buffer layer between the active layer and the Al cathode. The effects of the C6H5COOLi thickness on the performance of polymer solar cell are also investigated. Under 100 mW/cm2 white light illumination, the device with 1 nm thick C6H5COOLi as cathode buffer layer exhibits power conversion efficiency (PCE) as high as 3.41±0.07% and the device stability is greatly extended. Compared to the solar cell with LiF/Al cathode, the PCE is increased ca. 9.4%. Introduction of C6H5COOLi buffer layer effectively increases the shunt resistance and improves the photo-generated charge collection. The improved performance may attribute to the dissociation of semi-conducting C6H5COOLi upon deposition to liberate Li with a low work function, which reduces the interface resistance of the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportion. In addition, the C6H5COOLi layer may serve as an effective oxygen and moisture diffusion barrier for the organic solar cells. Therefore, C6H5COOLi is a promising candidate as an interlayer to improve the efficiency of electron collection and to reduce the ambience influence on the stability of polymer solar cells.
Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Enhanced performance and stability of polymer solar cells based on P3HT:PCBM blend using lithium benzoate (C6H5COOLi) as cathode buffer layer were achieved. ► The power conversion efficiency was 3.41% under the illumination of 100 mW/cm2, ∼9.4% enhancement compared to the device with LiF as a cathode buffer layer. ► A simple C6H5COOLi interlayer is promising to reduce the ambience influence on the stability of normal geometry devices.
