Ce3+,Cr3+co-doped garnet phosphors with yellow and near-infrared emission for white and near-IR dual-mode pc-LEDs
Cr3+-activated phosphors with adjustable near-infrared(NIR)emission have attracted considerable attention due to their diverse applications across various fields.While modifying the emission wavelength of Cr3+can be achieved by adjusting its coordination environment,the parity-forbidden d-d transition presents a challenge by limiting absorption and resulting in a low external quantum efficiency(EQE)in Cr3+-doped phosphors.Moreover,longer emission wavelengths often coincide with reduced thermal stability.To address these issues,energy transfer from a sensitizer to Cr3+has been proposed as a strategy to enhance both EQE and thermal stability of NIR emission.The selection of an appropriate host structure is crucial.In this study,a garnet structure,Ca2LuMgScSi3O12,was identified as a promising candidate for achieving efficient broadband NIR emission under blue light excitation.Specifically,Ca2LuMgScSi3O12∶Ce3+exhibited a yellow emission with exceptional internal quantum efficiency and EQE of up to 94.6%and 64.8%,respectively.By leveraging efficient energy transfer from Ce3+to Cr3+,the Ca2LuMgScSi3-O12∶Ce3+,Cr3+phosphors exhibited tunable yellow to NIR emission.Notable,the highest EQE recorded for Ca2LuMgScSi3O12∶Ce3+,Cr3+was 56.9%,significantly surpass-ing that of the Cr3+single-doped counterpart.Furthermore,the co-doped phosphor demonstrated thermal stability com-parable to that of Ce3+single-doped phosphor.Of particular significance,the developed prototype pc-LED emitted a com-bination of broadband white and NIR light,demonstrating potential applications in solar-like lighting,food analysis,and biomedical imaging.
garnetphosphorenergy transferCr3+near-infrared
吴其芃、唐嘉丽、韩跃、廖淑珍、张信果、廉世勋、张吉林
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Key Laboratory of Light Energy Conversion Materials of Hunan Province College,Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research(Ministry of Education),College of Chemistry and Chemical Engineering,Hunan Normal University,Changsha 410081,China
Hunan Provincial Key Laboratory of Environmental Catalysis and Waste Recycling,College of Materials and Chemical Engineering,Hunan Institute of Engineering,Xiangtan 411104,China
Guangdong Provincial Key Laboratory of New Drug Screening,School of Pharmaceutical Sciences,Southern Medical University,Guangzhou 510515,China
garnet phosphor energy transfer Cr3+ near-infrared