A study of stabilization of P3HT/PCBM organic solar cells by photochemical active TiOx layer

Abstract We describe a study of the stabilization behavior of P3HT/PCBM organic solar cells under air and UV irradiation using a 20 nm thin TiO x protection layer made by partial hydrolysis of a Ti-alkoxide and spin coating in air. Data on the degradation of solar cell performance under air and under UV exposure are presented indicating that significant improvements are observed with TiO x layer protection. The protection mechanism has been investigated by transmission IR and UV spectroscopy and by ESR spectroscopy. The results of this study suggest how sol–gel derived TiO x films containing organic functionalities serve as effective passivation films for protection from oxygen when excited by photons, where the photooxidation of the bound organic moieties causes oxygen gas scavenging.

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