The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highes...The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highest occupied molecular orbital(HOMO)level and low degree of crystallinity of the star donor polymer PCE10 limit its application in PDI-based Organic solar cells(OSCs).In this study,two benzo[1,2-b:4,5-b′]difuran(BDF)-based narrow-bandgap polymer donors,PBDF and PBDFCl,were synthesized to improve the photovoltaic performance of PDI-based OSCs.The smaller BDF moiety with higher electronegativity endows the resulting polymers with stronger aggregation and lower HOMO energy levels.The power conversion efficiency(PCE)value of the PBDF:Ph(PDI)3-based OSCs was 7.24%,which is much higher than that of PCE10-based OSCs(6.09%).Further chlorination of the conjugated side chain elevated the PCE to 8.84%,which is 1.4 times higher than that of PCE10-based OSCs.These results demonstrate the significant contribution of designing novel narrow-bandgap polymer donors to boost the PCE of PDI-based OSCs and highlight the importance of matching the aggregation behaviors of polymeric donor materials with that of NFAs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52273195 and 51973169)Young Top-notch Talent Cultivation Program of Hubei Province,Natural Science Foundation of Hubei Province(No.2022CFB097)。
文摘The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highest occupied molecular orbital(HOMO)level and low degree of crystallinity of the star donor polymer PCE10 limit its application in PDI-based Organic solar cells(OSCs).In this study,two benzo[1,2-b:4,5-b′]difuran(BDF)-based narrow-bandgap polymer donors,PBDF and PBDFCl,were synthesized to improve the photovoltaic performance of PDI-based OSCs.The smaller BDF moiety with higher electronegativity endows the resulting polymers with stronger aggregation and lower HOMO energy levels.The power conversion efficiency(PCE)value of the PBDF:Ph(PDI)3-based OSCs was 7.24%,which is much higher than that of PCE10-based OSCs(6.09%).Further chlorination of the conjugated side chain elevated the PCE to 8.84%,which is 1.4 times higher than that of PCE10-based OSCs.These results demonstrate the significant contribution of designing novel narrow-bandgap polymer donors to boost the PCE of PDI-based OSCs and highlight the importance of matching the aggregation behaviors of polymeric donor materials with that of NFAs.
