Aging of flat heterojunction zinc phthalocyanine/fullerene C₆₀ organic solar cells
This work addresses the long-term aging of organic solar cells based on a flat zinc phthalocyanine (ZnPc)/C<sub>60</sub> heterojunction. We investigate both the typical degradation behavior of the short circuit current and of the saturated photocurrent, defined as <em>I</em>(...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Elsevier
2010
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| Summary: | This work addresses the long-term aging of organic solar cells based on a flat zinc phthalocyanine (ZnPc)/C<sub>60</sub> heterojunction. We investigate both the typical degradation behavior of the short circuit current and of the saturated photocurrent, defined as <em>I</em>(−1<em>V</em>). The latter remains constant after a relatively small initial decay, which is directly related to a substantial reduction of the contribution of excitons generated in C<sub>60</sub> to the external quantum efficiency. Mass spectroscopy analysis of the organic material after aging revealed oxidized C<sub>60</sub> and sub-products thereof. The reduction of <em>I</em>(−1<em>V</em>) is thus attributed to the reaction of C<sub>60</sub> molecules with oxygen impurities. The results strongly suggest that ZnPc/C<sub>60</sub> photovoltaic cells are intrinsically very stable on a time scale of thousand of hours if such reactions are prevented. © 2009 Elsevier B.V. |
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