Low efficiency and spectral instability caused by the surface defects have been considerable issues for the mixed-halogen blue emitting perovskite quantum dots light-emitting diodes(PeQLEDs).Here,an in situ surface pa...Low efficiency and spectral instability caused by the surface defects have been considerable issues for the mixed-halogen blue emitting perovskite quantum dots light-emitting diodes(PeQLEDs).Here,an in situ surface passivation to perovskite quantum dots(PeQDs)is realized by introducing the metal cations competitive lattice occupancy assisted with acid-etching,in which the longchain,insulating and weakly bond surface ligands are removed by addition of octanoic acid(OTAC).Meanwhile,the dissolved A-site cations(Na^(+))compete with the protonated oleyl amine and are subsequently anchored to the surface vacancies.The preadded lead bromide,acting as inorganic ligands,demonstrates strong bonding to the uncoordinated surface ions.The as-synthesized PeQDs show the boosted photoluminescence quantum yield(PLQY)and superior stability with longer lifetime.As a result,the PeQLEDs(470 nm)based on the OTAC-Na PeQDs exhibit an external quantum efficiency of 8.42%in the mixed halogen PeQDs(CsPb(Br_(x)Cl_(1−x))_(3)).Moreover,the device exhibits superior spectra stability with negligible shift.Our competition mechanism in combination with in situ passivation strategy paves a new way for improving the performance of blue PeQLEDs.展开更多
基金Key Research and Development Project of Anhui Province of China,Grant/Award Number:2023t07020005Anhui Innovation and Entrepreneurship Support Plan for Returned Overseas Students,Grant/Award Number:2022LCX018+2 种基金National Natural Science Foundation of China,Grant/Award Number:U1632151Open Project of Jiangsu Key Laboratory for Carbon‐Based Functional Materials&Devices,Grant/Award Number:KJS1802Natural Science Foundation of Anhui Province,China,Grant/Award Number:2308085QE137。
文摘Low efficiency and spectral instability caused by the surface defects have been considerable issues for the mixed-halogen blue emitting perovskite quantum dots light-emitting diodes(PeQLEDs).Here,an in situ surface passivation to perovskite quantum dots(PeQDs)is realized by introducing the metal cations competitive lattice occupancy assisted with acid-etching,in which the longchain,insulating and weakly bond surface ligands are removed by addition of octanoic acid(OTAC).Meanwhile,the dissolved A-site cations(Na^(+))compete with the protonated oleyl amine and are subsequently anchored to the surface vacancies.The preadded lead bromide,acting as inorganic ligands,demonstrates strong bonding to the uncoordinated surface ions.The as-synthesized PeQDs show the boosted photoluminescence quantum yield(PLQY)and superior stability with longer lifetime.As a result,the PeQLEDs(470 nm)based on the OTAC-Na PeQDs exhibit an external quantum efficiency of 8.42%in the mixed halogen PeQDs(CsPb(Br_(x)Cl_(1−x))_(3)).Moreover,the device exhibits superior spectra stability with negligible shift.Our competition mechanism in combination with in situ passivation strategy paves a new way for improving the performance of blue PeQLEDs.
