摘要
Two conjugated polymers(PulDTBD and PulDTQ)with un symmetric side chai ns have been prepared for polymer solar cells using two other polymers(PIDTBD and PIDTQ)with symmetric side chains as control compounds.The combi nation of methyl a nd 4-hexylphenyl side chai ns on the same bridged carb on can en sure good solubility,decrease tt-tt stacking dista nces,and bring proper miscibility with PC71BM simultaneously.Therefore,the corresp on ding polymer solar cells(PSCs)based on donor polymers with un symmetric side chains exhibited enhanced short-circuit current density(■)and power conversion efficiency(PCE)compared with those of control polymers.The PIDTBD and PIDTQ based devices possessed low PCE of 2.13%and 1.48%,while PCEs of devices based on PulDTBD and PulDTQ were improved to 3.93%and 4.12%,respectively.The results demonstrate that unsymmetric side chain engineering of conjugated polymers is an effective approach to achieve high performance PSCs.
