Effect of structural modulation of polymeric 3rd component on the performance of polymer solar cells
발표자
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초록
내용
The properties of co-absorbing wide band-gap polymers re fine-tuned via the insertion of two different appropriate electron-acceptor units on their backbone in different ratios, and the resulting polymers are utilized as a co-absorbent on ter-PSCs. The copolymerization of benzodithiophene, pyrrolopyrrole-1,3-dione, and difluoro-benzothiadiazole derivatives at three different ratios, 1.00:1.00:0.00, 1.00:0.50:0.50, and 1.00:0.25:0.75, produces the polymers P1–P3. The crystallinity of the polymers is increased in the order of P1 ＜ P2 ＜ P3. The inclusion of 20 wt% of each of P1, P2, and P3 on a P4 (=PTB7-Th):PC70BM blend offers PCEs of 9.31%, 9.60%, and 9.85%, respectively, which are higher than that of the bi-PSC made using a blend of P4:PC70BM (PCE = 8.20%). The improved absorption, crystallinity, and carrier mobilities of the ternary blends are the main reasons for their enhanced photovoltaic performance compared with the binary blends.