Broadband near-infrared(NIR)phosphor-converted light-emitting diodes(pc-LEDs)are considered to be at the forefront of the development of next-generation NIR light sources.However,the performance of NIR pc-LEDs is seve...Broadband near-infrared(NIR)phosphor-converted light-emitting diodes(pc-LEDs)are considered to be at the forefront of the development of next-generation NIR light sources.However,the performance of NIR pc-LEDs is severely limited due to the narrow band emission,low quantum efficiency,and thermal quenching of NIR-emitting materials.Herein,an efficient and thermally stable broadband NIR LaMgGa_(11)O_(19):Cr^(3+),Yb^(3+)(LMG:Cr^(3+),Yb^(3+))phosphor has been successfully designed by[Cr^(3+)-Yb^(3+)]codoping.The broadband emission phenomenon of LaMgGa_(11)O_(19):Cr^(3+)was confirmed to be due to selective lattice occupancy of Cr^(3+)ions based on the analysis of crystal structures,crystal field calculations,and fluorescence lifetimes.The NIR emission spectra in the range of 1000-1200 nm were enriched by using the highly efficient energy transfer of Cr^(3+)→Yb^(3+)ions and the energy transfer mechanism is discussed in detail.The prepared LMG:Cr^(3+),Yb^(3+)phosphors exhibit highly efficient ultra-broadband NIR emission from 650 to 1200 nm under 440 nm excitation with high internal and external quantum efficiencies of 94.2%/40.5% and excellent luminescence thermal stability of 89.3%@373 K.A NIR pc-LED prototype was fabricated by combining the optimized phosphor with a commercial 440 nm blue LED chip,providing 84.5 mW NIR output power at a 350 mA driving current.Finally,the potential applications of the phosphor in night vision lighting and non-destructive testing were demonstrated.The results show that this work is expected to provide a new strategy for efficient ultra-broadband NIR phosphor design.展开更多
Lead-free halide double perovskite Cs_(2)AgInCl_(6 )has become the research hotspot in the optoelectronic fields.It is a challenge to utilize the lattice doping by different lanthanide ions with rich and unique photol...Lead-free halide double perovskite Cs_(2)AgInCl_(6 )has become the research hotspot in the optoelectronic fields.It is a challenge to utilize the lattice doping by different lanthanide ions with rich and unique photoluminescence(PL)emissions for emerging photonic applications.Here,we successfully incorporated Dy^(3+),Sm^(3+),and Tb3+ions into Cs_(2)AgInCl_(6) nanocrystals(NCs)by the hot-injection method,bringing diverse PL emissions of yellowish,orange,and green light in Cs_(2)AgInCl_(6):Ln^(3+)(Ln^(3+)=Dy^(3+),Sm^(3+),Tb^(3+)).Moreover,benefiting from the energy transfer process,Sm^(3+)and Tb^(3+)ion-codoped Cs_(2)AgInCl_(6) NCs achieved tunable emission from green to yellow orange and a fluorescent pattern from the as-prepared NC-hexane inks by spray coating was made to show its potential application in fluorescent signs and anticounterfeiting technology.This work indicates that lanthanide ions could endow Cs_(2)AgInCl_(6) NCs the unique and tunable PL properties and stimulate the development of lead-free halide perovskite materials for new optoelectronic applications.展开更多
基金supported by the National Natural Science Foundation of China(No.12274144,22361132525,and 52472161)the Guangdong Provincial Science and Technology Project(No.2022A1515010229)+1 种基金the Russian Science Foundation(grant 24-43-00006)the Undergraduate Innovation and Entrepreneurship Training Program grant for Zixi Chen.
文摘Broadband near-infrared(NIR)phosphor-converted light-emitting diodes(pc-LEDs)are considered to be at the forefront of the development of next-generation NIR light sources.However,the performance of NIR pc-LEDs is severely limited due to the narrow band emission,low quantum efficiency,and thermal quenching of NIR-emitting materials.Herein,an efficient and thermally stable broadband NIR LaMgGa_(11)O_(19):Cr^(3+),Yb^(3+)(LMG:Cr^(3+),Yb^(3+))phosphor has been successfully designed by[Cr^(3+)-Yb^(3+)]codoping.The broadband emission phenomenon of LaMgGa_(11)O_(19):Cr^(3+)was confirmed to be due to selective lattice occupancy of Cr^(3+)ions based on the analysis of crystal structures,crystal field calculations,and fluorescence lifetimes.The NIR emission spectra in the range of 1000-1200 nm were enriched by using the highly efficient energy transfer of Cr^(3+)→Yb^(3+)ions and the energy transfer mechanism is discussed in detail.The prepared LMG:Cr^(3+),Yb^(3+)phosphors exhibit highly efficient ultra-broadband NIR emission from 650 to 1200 nm under 440 nm excitation with high internal and external quantum efficiencies of 94.2%/40.5% and excellent luminescence thermal stability of 89.3%@373 K.A NIR pc-LED prototype was fabricated by combining the optimized phosphor with a commercial 440 nm blue LED chip,providing 84.5 mW NIR output power at a 350 mA driving current.Finally,the potential applications of the phosphor in night vision lighting and non-destructive testing were demonstrated.The results show that this work is expected to provide a new strategy for efficient ultra-broadband NIR phosphor design.
基金the National Natural Science Foundation of China(grant numbers 51961145101 and 51972118)the Fundamental Research Funds for the Central Universities(grant number FRFTP-18-002C1)+2 种基金the Guangzhou Science&Technology Project(202007020005)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(grant number 2017BT01X137)This work was also funded by RFBR according to the research project no.19-52-80003.
文摘Lead-free halide double perovskite Cs_(2)AgInCl_(6 )has become the research hotspot in the optoelectronic fields.It is a challenge to utilize the lattice doping by different lanthanide ions with rich and unique photoluminescence(PL)emissions for emerging photonic applications.Here,we successfully incorporated Dy^(3+),Sm^(3+),and Tb3+ions into Cs_(2)AgInCl_(6) nanocrystals(NCs)by the hot-injection method,bringing diverse PL emissions of yellowish,orange,and green light in Cs_(2)AgInCl_(6):Ln^(3+)(Ln^(3+)=Dy^(3+),Sm^(3+),Tb^(3+)).Moreover,benefiting from the energy transfer process,Sm^(3+)and Tb^(3+)ion-codoped Cs_(2)AgInCl_(6) NCs achieved tunable emission from green to yellow orange and a fluorescent pattern from the as-prepared NC-hexane inks by spray coating was made to show its potential application in fluorescent signs and anticounterfeiting technology.This work indicates that lanthanide ions could endow Cs_(2)AgInCl_(6) NCs the unique and tunable PL properties and stimulate the development of lead-free halide perovskite materials for new optoelectronic applications.
