Voltage loading-induced change in the electroluminescence(EL)wavelength of mixed halide perovskite light-emitting diodes(PeLEDs),so-called color-shift,has become an inevitable phenomenon,which is seriously unfavorable...Voltage loading-induced change in the electroluminescence(EL)wavelength of mixed halide perovskite light-emitting diodes(PeLEDs),so-called color-shift,has become an inevitable phenomenon,which is seriously unfavorable to their applications in lighting and display.Here,we achieve color-stable blue PeLEDs via a hydrogen-bonded amine-group doping strategy.Selecting guanidine(GA)or formamidinium(FA)as amine-group(-NH_(2))doping source for CsPbBr_(x)Cl_(3-x)quantum dots(QDs),experimental and theoretical results reveal that the strong N-H…X(X=Br/Cl)bonding can be produced between-NH_(2)dopants and Pb-X lattices,thereby increasing the migration barrier of halide anions.Resultantly,color-stable sky-blue devices were realized with emission peaks fixed at 490.5(GA)and 492.5(FA)nm without any obvious shift as the voltage increases,in sharp contrast devices without N-H…X producing a 15 nm red-shift from 487 to 502 nm.Not only that,maximum external quantum efficiency is improved to 3.02%and 4.14%from the initial 1.3%.This finding offers a convenient boulevard to achieve color-stable PeLEDs with high efficiency.展开更多
基金the National Natural Science Foundation of China(61725402,51922049)the Fundamental Research Funds for the Central Universities(30919012107,30920032102)+2 种基金the National“Ten Thousand Talents Plan”Leading Talents(W03020394)the Six Top Talent Innovation Teams of Jiangsu Province(TD-XCL-004)the Natural Science Foundation of Jiangsu Province(BK2018002)。
文摘Voltage loading-induced change in the electroluminescence(EL)wavelength of mixed halide perovskite light-emitting diodes(PeLEDs),so-called color-shift,has become an inevitable phenomenon,which is seriously unfavorable to their applications in lighting and display.Here,we achieve color-stable blue PeLEDs via a hydrogen-bonded amine-group doping strategy.Selecting guanidine(GA)or formamidinium(FA)as amine-group(-NH_(2))doping source for CsPbBr_(x)Cl_(3-x)quantum dots(QDs),experimental and theoretical results reveal that the strong N-H…X(X=Br/Cl)bonding can be produced between-NH_(2)dopants and Pb-X lattices,thereby increasing the migration barrier of halide anions.Resultantly,color-stable sky-blue devices were realized with emission peaks fixed at 490.5(GA)and 492.5(FA)nm without any obvious shift as the voltage increases,in sharp contrast devices without N-H…X producing a 15 nm red-shift from 487 to 502 nm.Not only that,maximum external quantum efficiency is improved to 3.02%and 4.14%from the initial 1.3%.This finding offers a convenient boulevard to achieve color-stable PeLEDs with high efficiency.
