Constructing ideal P-i-N-like network morphology and extending exciton diffusion length(L_(D))are considered bottleneck factors to further improve the power conversion efficiency(PCE)of organic photovoltaics(OPVs).How...Constructing ideal P-i-N-like network morphology and extending exciton diffusion length(L_(D))are considered bottleneck factors to further improve the power conversion efficiency(PCE)of organic photovoltaics(OPVs).However,simultaneous optimizations of the vertical phase separation morphology and L_(D)have rarely been reported.In this work,we apply a gradient thermal-annealing strategy to efficiently regulate the molecular stacking orientation and crystallinity of the polymer donor.The ordered molecular stacking significantly improves the exciton diffusion paths and enlarges the L_(D)from 19.47 nm(PM6-control)to 24.96 nm(PM6-target),enabling efficient exciton dissociation and charge transport.Moreover,the optimized crystallinity behavior inhibited PM6 film erosion from the upper acceptor solution.It ensured controlled donor-acceptor interpenetration,forming the desired pseudo planar heterojunction(PPHJ)structure.Eventually,benefiting from the ideal vertical morphology and the prolonged L_(D),the printing PPHJ(target)device achieves an outstanding PCE of 18.20%with suppressed non-radiative recombination losses(0.212 eV)and enhanced fill factor(78.2%),which is one of the top values for the reported eco-friendly printing binary OPVs.This study demonstrates a simple but feasible method to further improve the performance of polymer solar cells.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(52333006 and 52303232)Jiangxi Provincial Natural Science Foundation(20242BAB20184)+1 种基金Graduate Innovation Fund of Jiangxi Province(YC2024-S267)Guangdong Basic and Applied Basic Research Foundation(2023A1515110160).
文摘Constructing ideal P-i-N-like network morphology and extending exciton diffusion length(L_(D))are considered bottleneck factors to further improve the power conversion efficiency(PCE)of organic photovoltaics(OPVs).However,simultaneous optimizations of the vertical phase separation morphology and L_(D)have rarely been reported.In this work,we apply a gradient thermal-annealing strategy to efficiently regulate the molecular stacking orientation and crystallinity of the polymer donor.The ordered molecular stacking significantly improves the exciton diffusion paths and enlarges the L_(D)from 19.47 nm(PM6-control)to 24.96 nm(PM6-target),enabling efficient exciton dissociation and charge transport.Moreover,the optimized crystallinity behavior inhibited PM6 film erosion from the upper acceptor solution.It ensured controlled donor-acceptor interpenetration,forming the desired pseudo planar heterojunction(PPHJ)structure.Eventually,benefiting from the ideal vertical morphology and the prolonged L_(D),the printing PPHJ(target)device achieves an outstanding PCE of 18.20%with suppressed non-radiative recombination losses(0.212 eV)and enhanced fill factor(78.2%),which is one of the top values for the reported eco-friendly printing binary OPVs.This study demonstrates a simple but feasible method to further improve the performance of polymer solar cells.
