Impact of charge transport on current-voltage characteristics and power-conversion efficiency of organic solar cells
- This work elucidates the impact of charge transport on the photovoltaic properties of organic solar cells. Here we show that the analysis of current-voltage curves of organic solar cells under illumination with the Shockley equation results in values for ideality factor, photo-current and parallel resistance, which lack physical meaning. Drift-diffusion simulations for a wide range of charge-carrier mobilities and illumination intensities reveal significant carrier accumulation caused by poor transport properties, which is not included in the Shockley equation. As a consequence, the separation of the quasi Fermi levels in the organic photoactive layer (internal voltage) differs substantially from the external voltage for almost all conditions. We present a new analytical model, which considers carrier transport explicitly. The model shows excellent agreement with full drift-diffusion simulations over a wide range of mobilities and illumination intensities, making it suitable for realistic efficiency predictions for organic solarThis work elucidates the impact of charge transport on the photovoltaic properties of organic solar cells. Here we show that the analysis of current-voltage curves of organic solar cells under illumination with the Shockley equation results in values for ideality factor, photo-current and parallel resistance, which lack physical meaning. Drift-diffusion simulations for a wide range of charge-carrier mobilities and illumination intensities reveal significant carrier accumulation caused by poor transport properties, which is not included in the Shockley equation. As a consequence, the separation of the quasi Fermi levels in the organic photoactive layer (internal voltage) differs substantially from the external voltage for almost all conditions. We present a new analytical model, which considers carrier transport explicitly. The model shows excellent agreement with full drift-diffusion simulations over a wide range of mobilities and illumination intensities, making it suitable for realistic efficiency predictions for organic solar cells.…
| Author details: | Uli Würfel, Dieter NeherORCiDGND, Annika Spies, Steve AlbrechtORCiDGND |
|---|---|
| DOI: | https://doi.org/10.1038/ncomms7951 |
| ISSN: | 2041-1723 |
| Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/25907581 |
| Title of parent work (English): | Nature Communications |
| Publisher: | Nature Publ. Group |
| Place of publishing: | London |
| Publication type: | Article |
| Language: | English |
| Year of first publication: | 2015 |
| Publication year: | 2015 |
| Release date: | 2017/03/27 |
| Volume: | 6 |
| Number of pages: | 9 |
| Funding institution: | Deutsche Forschungsgemeinschaft DFG [SPP1355]; BMBF [FKZ 03IS2151D] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| Peer review: | Referiert |
| Publishing method: | Open Access |
