[21a-E101-1~12] 12.5 Organic solar cells

[21a-E101-4] Magnesium Tetraethynylporphyrin Bearing Four Selenium-Substituted Diketopyrrolopyrrole units for bulk heterojunction Organic Solar Cells

〇Takafumi Nakagwa¹, Huan Wang², Keisuke Ogimi³, Yutaka Matsuo^1,2,4 (1.Tokyo Univ., 2.USTC, 3.TIRI, 4.Nagoya Univ.)

Keywords:porphyrin, magnesium, diketopyrrolopyrrole

Three magnesium porphyrin-based donor materials (2a, Mg-TEP-(Se-DPP)₄; 2b, Mg-TEP-(S-DPP-Th)₄and 2c, Mg-TEP-(Se-DPP-Th)₄) bearing four electron-deficient diketopyrrolopyrroles (DPP)s with or without alkyl-thiophenes as end-caps are designed and synthesized, and their optical and electrochemical properties were investigated in-depth. All the three molecules show wide and strong absorption across from visible and near infrared region, narrow energy band gap, matched energy levels with PC₆₁BM and PC₇₁BM regularly. We applied two strategies to optimize the molecular structure and expected that these molecules will achieve outstanding performance in photovoltaic device. The optimized device based 2a:PC₆₁BM was obtained with highest PCEs of 6.09% after solvent vapor annealing, which can be ascribed to efficient exciton dissociation, balanced carrier mobility, suppressed bimolecular recombination of the more ordered morphology which facilitating achieve higher J_SCand FF.