Organic Solar Cells
Dieter Meissner1991, Advanced Materials
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Abstract
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The paper discusses the potential of organic solar cells as a regenerative energy source, comparing their efficiencies and mechanisms with inorganic semiconductor cells. Although organic solar cells have shown significant progress since the 1970s, achieving efficiencies of up to 0.5%, challenges remain due to their complex energy-band structures and lower charge-carrier mobilities. The article provides an overview of organic solar cell structures, fabrication methods, characteristics, and presents a qualitative understanding of their operational principles using classical semiconductor theories.
Key takeaways
- According to the classical theories, on p-type and n-type doping of an intrinsic material new energy levels are introduced in the band gap close to the band edges.
- In most cases, the conductivity can be increased in p-type materials by chemical "doping" with acceptor-like molecules (dioxygen, halogens, o-chloranil, trinitrofluorenone, tetracyanochinodimethane), or in n-type materials by "doping" with donor-like molecules like ammonia or phenothiazine.
- For example, while an increase of conductivity in 0,-containing atmospheres (reduced H, content) indicates a p-type conductivity, an n-type material is characterized by D. Wohrle, D. Meissner/Organic Solar Cells the inverse behavior.
- In every case shown, the p-type layers contain 0,, whereas "doping" with H, or NH, was used to influence the n-type layer (No.
- For the n-type material, "doping" with strong electron donors leads to a shift towards the conduction band.
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