摘要
Finding effective molecular design strategies to enable efficient charge generation,high charge transport,and small energy loss is a longstanding challenge for developing high-performance all-polymer solar cells(all-PSCs).Here,we designed and synthesized a fused-aromatic-ring-constructed near-infrared(NIR)polymer acceptor(PA)PYT-Tz with fused-ring benzotriazole(BTz)-based A’-DAD-A’structure as electron-deficient-core,n-nonane as alkyl-side-chain and thiophene asπ-bridge,and achieved a power conversion efficiency(PCE)of 15.10%for the all-PSCs with PYT-Tz as acceptor and a wide-bandgap PBDB-T as donor.A control PA PYT reported by our lab recently was introduced for investigating the synergistic effect of the electron-deficient-core and alkyl-side-chain on the optoelectronic properties and photovoltaic performance of the n-type PAs.Compared with PYT,the designed PYT-Tz exhibits intense and red-shifted absorption,upshifted energy levels,high electron mobility and ordered molecular packing in the active layers,and,blended with PBDB-T,yields the efficient hole injection,ultrafast charge generation,and the decreased non-radiative recombination loss of 0.17 eV.Of note is that the PCE of 15.10%is one of the highest PCE values for an all-PSC reported to date.Our results indicate BTz-based fused-aromatic-ring-constructed PAs are promising NIR acceptors in the all-PSCs.
基金
This work was financially supported by the National Natural Science Foundation of China(Nos.21702154 and 51773157)
We also thank the support of the opening project of Key Laboratory of Materials Processing and Mold and Beijing National Laboratory for Molecular Sciences(No.BNLMS201905).
