Journal article
Substituted 2,1,3-Benzothiadiazole- And Thiophene-Based Polymers for Solar Cells - Introducing a New Thermocleavable Precursor
Alkoxysubstituted and unsubstituted 2,1,3-benzothiadiazoles were prepared and copolymerized with substituted and unsubstituted thiophenes using both Stille and Yamamoto cross-coupling reactions. One class of the materials bore thermally labile ester groups. The materials were all found to have a reduced band gap in the range of 1.69−1.75 eV and were explored in polymer photovoltaic devices as mixtures with the soluble fullerene PCBM.
High open circuit voltages of up to 0.93 V and power conversion efficiencies (PCE) of up to 2.22% was observed for materials without the thermally labile groups. The thermocleavable materials have the advantage that they are insoluble after a thermal treatment, enabling a larger degree of processing freedom when preparing multilayer devices and they provide a better operational stability for the devices.
So far the process of thermocleavage has led to poorer device performance than for the soluble precursor polymers; however, we found processing conditions that lead to a higher performance for the thermocleaved product, where open circuit voltages of up to 0.9 V could be obtained with power conversion efficiencies of up to 0.42%, representing a doubling as compared to the soluble precursor polymer.
Copyright © 2009 American Chemical Society
Language: | English |
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Year: | 2009 |
Pages: | 4669-4675 |
ISSN: | 15205002 and 08974756 |
Types: | Journal article |
DOI: | 10-1021/cm901937d |
ORCIDs: | Petersen, Martin Helgesen , Gevorgyan, Suren and Krebs, Frederik C |