| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 78803 | Solar Energy Materials and Solar Cells | 2011 | 5 Pages |
We present the effects of a concentration graded Li:Al cathode when it is made by one-step evaporation method using single alloy sources on the performance of organic solar cells. The concentration profile of the Li:Al cathode and related interface energy levels were investigated by means of secondary ion mass spectroscopy and ultraviolet photoelectron spectroscopy, in comparison with those of a common Al cathode. The results indicate that interfacial lithium accumulation introduces a cascade decrease of the work function (WF) of the cathode. The WF graded cathode applied to bulk heterojunction solar cells resulted in increased short circuit current and power conversion efficiency. Furthermore, the Li:Al cathode avoids the formation of interface Al–C complex, which may cause disruption of electron transport.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We present the effects of a concentration graded Li:Al alloy cathode of organic solar cells. ► The graded cathode was applied to solar cells, resulting in increased power conversion efficiency. ► The Li:Al cathode showed more reduced formation of Al–C complex than the Al and LiF/Al cathodes.
