Owing to their unique optical properties and nontoxicity,lead-free halide double perovskite nanocrystals are of interest for widespread applications.Herein,the colloid synthesis and photoluminescenc e property of Ag^(...Owing to their unique optical properties and nontoxicity,lead-free halide double perovskite nanocrystals are of interest for widespread applications.Herein,the colloid synthesis and photoluminescenc e property of Ag^(+)-Eu^(3+)codoped Cs_(2)NaInCl_(6)nanocrystals were investigated.The pe rovskite nanocrystals exhibit a broad warm-white photo luminescence with correlated color temperature(CCT)of 3447 K and color rendering index(CRI)of 90.2,and the means of codoping would improve its optical performance.A fast energy transfer and a long-lived self-trapped excitons state are unveiled by the femtosecond transient absorption spectra.The fast energy transfer from the self-trapped excitons of host nanocrystals to the Eu^(3+)ions is helpful to achieve a broad photoluminescence,and the quantum yield of Cs_(2)NaInCl_(6):0.05Ag^(+)-Eu^(3+)anocrystals can be enha nced to 69.5%.There is a large exciton binding energy and strong electron-phonon interaction in the codoped perovskite nanocrystals.The efficient and excellent air-stable double perovskite nanocrystals would be considered as a single-component phosphor for warm-white lighting.展开更多
Phosphor-converted white light-emitting diodes for indoor illumination need to be warm-white(i.e.,correlated color temperature,4000 K)with good color rendition(i.e.,color rendering index.80).However,no single-phosphor...Phosphor-converted white light-emitting diodes for indoor illumination need to be warm-white(i.e.,correlated color temperature,4000 K)with good color rendition(i.e.,color rendering index.80).However,no single-phosphor,single-emitting-center-converted white light-emitting diodes can simultaneously satisfy the color temperature and rendition requirements due to the lack of sufficient red spectral component in the phosphors’emission spectrum.Here,we report a new yellow Ba_(0.93)Eu_(0.07)Al_(2)O_(4) phosphor that has a new orthorhombic lattice structure and exhibits a broad yellow photoluminescence band with sufficient red spectral component.Warm-white emissions with correlated color temperature,4000 K and color rendering index.80 were readily achieved when combining the Ba_(0.93)Eu_(0.07)Al_(2)O_(4) phosphor with a blue light-emitting diode(440–470 nm).This study demonstrates that warm-white light-emitting diodes with high color rendition(i.e.,color rendering index.80)can be achieved based on single-phosphor,single-emitting-center conversion.展开更多
采用逐步热注射法合成了用于白光LED的Cu In S2/Zn S(CIS/Zn S)核壳结构量子点。通过调整Cu/In的比率,在Cu In S2(CIS)量子点的基础上,合成了发射波长在570~650 nm之间可调的CIS/Zn S量子点。与CIS量子点的低量子产率相比,具有核壳结构...采用逐步热注射法合成了用于白光LED的Cu In S2/Zn S(CIS/Zn S)核壳结构量子点。通过调整Cu/In的比率,在Cu In S2(CIS)量子点的基础上,合成了发射波长在570~650 nm之间可调的CIS/Zn S量子点。与CIS量子点的低量子产率相比,具有核壳结构的CIS/Zn S量子点的量子产率达到了78%。通过在黄光荧光粉YAG∶Ce3+表面旋涂CIS/Zn S量子点的方式制备了暖白光LED器件。在工作电流为10 m A时,暖白光LED的发光效率达到了244.58 lm/W。由于CIS/Zn S量子点的加入,所制备的白光LED器件的显色指数达到86.7且发光颜色向暖色调发生了转移,相应的色坐标为(0.340 6,0.369 0)。展开更多
基金Project supported by the National Natural Science Foundation of China(61805134,11974229,22303044)Fundamental Research Program of Shanxi Province(202203021221121)+3 种基金China Postdoctoral Science Foundation(2022M711898)Natural Science Fo undation of Shandong Province(ZR2023QB135)Postdoctoral Innovation Project of Shandong Province(SDCX-ZG-202201004)Graduate Innovation Project in Shanxi Province(2024KY450)。
文摘Owing to their unique optical properties and nontoxicity,lead-free halide double perovskite nanocrystals are of interest for widespread applications.Herein,the colloid synthesis and photoluminescenc e property of Ag^(+)-Eu^(3+)codoped Cs_(2)NaInCl_(6)nanocrystals were investigated.The pe rovskite nanocrystals exhibit a broad warm-white photo luminescence with correlated color temperature(CCT)of 3447 K and color rendering index(CRI)of 90.2,and the means of codoping would improve its optical performance.A fast energy transfer and a long-lived self-trapped excitons state are unveiled by the femtosecond transient absorption spectra.The fast energy transfer from the self-trapped excitons of host nanocrystals to the Eu^(3+)ions is helpful to achieve a broad photoluminescence,and the quantum yield of Cs_(2)NaInCl_(6):0.05Ag^(+)-Eu^(3+)anocrystals can be enha nced to 69.5%.There is a large exciton binding energy and strong electron-phonon interaction in the codoped perovskite nanocrystals.The efficient and excellent air-stable double perovskite nanocrystals would be considered as a single-component phosphor for warm-white lighting.
基金ZWP acknowledges funding by the US National Science Foundation(CAREER DMR-0955908)ZJG acknowledges support by the National Basic Research Programs of China(973 program,No.2012CB932504)+4 种基金JDB was supported by the Materials Sciences and Engineering Division,Office of Basic Energy Sciences(BES),US Department of Energy(DOE).Use of the APS beamline 11-BM-B for synchrotron X-ray powder diffractionbeamline 34-ID-E for polychromatic Laue microdiffraction was supported by the Scientific User Facilities Division of BES,US DOE.Use of the APS beamline 20-BM-B for X-ray absorption near edge structure measurement by CJS was supported by US DOE under Contract no.DE-AC02-06CH11357 with Argonne National Laboratory.The TEM characterization was sponsored by Oak Ridge National Laboratory’s Shared Research Equipment(ShaRE)User program,which is sponsored by the Division of Scientific User Facilities of BES,US DOE.
文摘Phosphor-converted white light-emitting diodes for indoor illumination need to be warm-white(i.e.,correlated color temperature,4000 K)with good color rendition(i.e.,color rendering index.80).However,no single-phosphor,single-emitting-center-converted white light-emitting diodes can simultaneously satisfy the color temperature and rendition requirements due to the lack of sufficient red spectral component in the phosphors’emission spectrum.Here,we report a new yellow Ba_(0.93)Eu_(0.07)Al_(2)O_(4) phosphor that has a new orthorhombic lattice structure and exhibits a broad yellow photoluminescence band with sufficient red spectral component.Warm-white emissions with correlated color temperature,4000 K and color rendering index.80 were readily achieved when combining the Ba_(0.93)Eu_(0.07)Al_(2)O_(4) phosphor with a blue light-emitting diode(440–470 nm).This study demonstrates that warm-white light-emitting diodes with high color rendition(i.e.,color rendering index.80)can be achieved based on single-phosphor,single-emitting-center conversion.
