[21a-432-1~12] 12.5 Organic solar cells

[21a-432-7] Long-lived charge carriers in crystalline polymer solar cells

〇Shinnosuke Tokuda¹, Yasunari Tamai¹, Itaru Osaka², Hideo Ohkita¹ (1.Kyoto Univ., 2.Hiroshima Univ.)

Keywords:triplet exciton, transient absorption

Here, we performed transient absorption and transient photovoltage/photocurrent measurements for blend films of crystalline polymer PNOz4T and fullerenes C₆₀ or PC₇₁BM to measure charge carrier lifetimes. As a result, we found that the carrier lifetime of the C₆₀ blend is much shorter than that of the PC₇₁BM blend, and triplet excitons were generated through bimolecular recombination. These findings suggest that suppressing triplet formation is of primary importance to enhance charge carrier lifetime.