Effects of n-type perylene derivative as an additive on the power conversion efficiencies of polymer solar cells

摘要

The synthesized n-type perylene derivative, N,N'-bis-(5-bromopyridine-2-yI)-l,6,7,12-tetrakis(4-n-butoxyphenoxy)-3,4,9,10-perylene tetracarboxydiimide (PPyB), was applied to polymer solar cells as an additive in P3HT [poly(3-hexylthiophene)]:PCBM [[6,6]-phenyl C_(61) -butyric acid methyl ester] blend films. The addition of 1 wt% PPyB into a P3HT:PCBM layer led to a considerable improvement of over 70% in power conversion efficiency due to the enhanced short circuit current when compared with that of reference cell without an additive. Photoluminescence, X-ray measurements and carrier mobility studies revealed that the perylene additives increased electron mobility and contributed to more effective exci-ton dissociation due to the presence of the additive, PPyB, in the interfaces between the P3HT and PCBM domains.