White-light-emitting phosphors based on phosphate host matrix, KSrPO4 doped with Dy^3＋, were prepared by solid state reaction and their VUV luminescent properties were firstly investigated. The excitation band peakin...White-light-emitting phosphors based on phosphate host matrix, KSrPO4 doped with Dy^3＋, were prepared by solid state reaction and their VUV luminescent properties were firstly investigated. The excitation band peaking at 125-153 nm corresponding to the absorption of PO4^3- group exhibits very strong absorption. The phosphors emit warm-white luminescence under vacuum ultraviolet excitation of 147 nm, which consists of three main emission peaks located at 475, 570 and 662 nm, respectively.According to the luminescence and color chromaticity of the optimal sample KSrPO4：1 mol%Dy^3＋,1.3 mol%Li^＋, it can be a potential candidate for mercury-free fluorescent lamps.展开更多
Ion migration is a notorious problem in perovskite solar cells(PSCs)that severely mutilates device performance.Herein,a strategy to inhibit ion migration in situ is developed by using photoisomerization of azobenzene(...Ion migration is a notorious problem in perovskite solar cells(PSCs)that severely mutilates device performance.Herein,a strategy to inhibit ion migration in situ is developed by using photoisomerization of azobenzene(AZO)to immobilize cations in the lattice.During the nucleation process,the photoisomerized cis-AZO reacts with FA^(+),MA^(+)and Pb2+cations in the perovskite precursor by synergistic cation-πinteraction and Lewis base coordination,leading to heterogeneous nucleation to produce uniform perovskite film.Meanwhile,it accelerates conversion of intermediate yellowδ-phase to desired black aphase of FAPb I3for improved crystallinity with well-passivated grain surface.Consequently,defect density is effectively reduced for the perovskite film to demonstrate suppressed carrier recombination and enhanced carrier extraction.Subsequently,the solar cell efficiency is elevated from 21.29%to 23.58%with negligible J-V hysteresis.Long-term stability is also improved,with the bare device without any encapsulation retaining 84%of its initial efficiency after aging 744 hours in ambient.展开更多
基金Project supported by the National Key Research and Development Program of China(2016YFA0202403)National Natural Science Foundation of China(21603140,21641001)the Fundamental Research Funds for the Central Universities(GK201803036,GK201803029)
文摘White-light-emitting phosphors based on phosphate host matrix, KSrPO4 doped with Dy^3＋, were prepared by solid state reaction and their VUV luminescent properties were firstly investigated. The excitation band peaking at 125-153 nm corresponding to the absorption of PO4^3- group exhibits very strong absorption. The phosphors emit warm-white luminescence under vacuum ultraviolet excitation of 147 nm, which consists of three main emission peaks located at 475, 570 and 662 nm, respectively.According to the luminescence and color chromaticity of the optimal sample KSrPO4：1 mol%Dy^3＋,1.3 mol%Li^＋, it can be a potential candidate for mercury-free fluorescent lamps.
基金supported by the National Natural Science Foundation of China(21603140)the 111 Project(B21005)。
文摘Ion migration is a notorious problem in perovskite solar cells(PSCs)that severely mutilates device performance.Herein,a strategy to inhibit ion migration in situ is developed by using photoisomerization of azobenzene(AZO)to immobilize cations in the lattice.During the nucleation process,the photoisomerized cis-AZO reacts with FA^(+),MA^(+)and Pb2+cations in the perovskite precursor by synergistic cation-πinteraction and Lewis base coordination,leading to heterogeneous nucleation to produce uniform perovskite film.Meanwhile,it accelerates conversion of intermediate yellowδ-phase to desired black aphase of FAPb I3for improved crystallinity with well-passivated grain surface.Consequently,defect density is effectively reduced for the perovskite film to demonstrate suppressed carrier recombination and enhanced carrier extraction.Subsequently,the solar cell efficiency is elevated from 21.29%to 23.58%with negligible J-V hysteresis.Long-term stability is also improved,with the bare device without any encapsulation retaining 84%of its initial efficiency after aging 744 hours in ambient.
