Perovskite nanocrystals(PNCs)have recently become promising optoelectronic materials due to their excellent photophysical properties.However,the highly dynamic binding state between ligands and the surface of PNCs has...Perovskite nanocrystals(PNCs)have recently become promising optoelectronic materials due to their excellent photophysical properties.However,the highly dynamic binding state between ligands and the surface of PNCs has severely restricted their luminescent properties and stabilities.In this work,1,3-bisbenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid(cycle acid,CA)is introduced as both an etchant and a ligand upon post-synthetic surface treatment of PNCs.By removing the imperfect octahedrons[Pb X_(6)]^(4-)and passivating the surface defects synergistically,this treatment improves photoluminescence quantum yields from 76%to 95%and enhances the stability of PNCs against polar solvent,moisture,heat,and illumination.Meanwhile,CA can effectively and instantly recover the luminescence emission for aged PNCs.As a result,the CA-Cs Pb Br_(3)PNCs and CA-Cs Pb IxBr_(3-x)PNCs are applied as color-converting layers on a blue LED chip for warm white light-emitting diodes(WLEDs)with a color coordinate of(0.41,0.40).Importantly,the CA-based WLED device exhibits superior stability in operational conditions.展开更多
基金financial from the National Natural Science Foundation of China(22279039 and 20181194)the Chinese National 1000-Talent-Plan program+2 种基金the Innovation Project of Optics Valley Laboratory(OVL2021BG008)the Frontier of the Application Foundation of Wuhan Science and Technology Plan Project(2020010601012202)the Foundation of State Key Laboratory of New Textile Materials and Advanced Processing Technologies(FZ2021011)。
文摘Perovskite nanocrystals(PNCs)have recently become promising optoelectronic materials due to their excellent photophysical properties.However,the highly dynamic binding state between ligands and the surface of PNCs has severely restricted their luminescent properties and stabilities.In this work,1,3-bisbenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid(cycle acid,CA)is introduced as both an etchant and a ligand upon post-synthetic surface treatment of PNCs.By removing the imperfect octahedrons[Pb X_(6)]^(4-)and passivating the surface defects synergistically,this treatment improves photoluminescence quantum yields from 76%to 95%and enhances the stability of PNCs against polar solvent,moisture,heat,and illumination.Meanwhile,CA can effectively and instantly recover the luminescence emission for aged PNCs.As a result,the CA-Cs Pb Br_(3)PNCs and CA-Cs Pb IxBr_(3-x)PNCs are applied as color-converting layers on a blue LED chip for warm white light-emitting diodes(WLEDs)with a color coordinate of(0.41,0.40).Importantly,the CA-based WLED device exhibits superior stability in operational conditions.
