Enhanced efficiency in organic solar cells by introduction of conjugated polyelectrolytes with diverse acid derivatives as cathode buffer layer
발표자
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초록
내용
A polymer based on fluorene, poly[(9,9-bis(30-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dihexylfluorene)] (PFN), was introduced to different amounts and types of acid derivatives such as acetic acid (AA), 4-trifluoromethyl benzoic acid (CF3BA), trifluoroacetic acid (CF3AA), and 4-toluene sulfonic acid (TsOH) as the cathode buffer layer in inverted organic solar cells (OSCs) with PTB7-Th:PC71BM blend as the active layer. The power conversion efficiency (PCE) of the OSC with pristine ZnO was 8.7%, while the PCE of the OSCs with the 1.0 equivalent of AA, CF3BA, CF3AA, and TsOH was 9.9, 10.3, 10.3, and 10.6%, respectively. The OSCs based on PFN with acid derivatives exhibit reduced trap-assisted recombination and interfacial bimolecular recombination which suited well with the trend of the PCEs of the devices and also matched the trend of the acid dissociation constant of acid derivatives.