Research Article

Variation of the Side Chain Branch Position Leads to Vastly Improved Molecular Weight and OPV Performance in 4,8-dialkoxybenzo[1,2-b:4,5-b′]dithiophene/2,1,3-benzothiadiazole Copolymers

Figure 7

External quantum efficiency spectra of bulk heterojunction solar cells based on P1 (black), P2 (blue), and P3 (red) and PC61BM.
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