Comparative Study of Mn2+on Luminescence Properties in YAG∶Ce3+Phosphor Ceramics
Transition-metal Mn2+ion doped garnet phosphor ceramics are promising for laser lighting with high col-or rendering.However,the scheme for Mn2+doped garnet ceramics is still ambiguous due to the diversity of ionic ra-dii of Mn2+in different coordinate environment.In this study,two series of YAG∶Ce3+phosphor ceramics with differ-ent Mn2+concentrations occupying octahedral(OC)and dodecahedral(DO)lattice sites were fabricated by vacuum sintering.The crystal structure,photoluminescence,fluorescence decay curves,quantum efficiency and electro-lu-minescence properties were studied in detail.The garnet crystal structure with Mn2+occupying in octahedral(OC)sites was more stable under the premise of doping SiO2 as charge and volume compensator.Therefore,the quantum efficiency of the OC series samples was higher than that of the DO series,in case the Mn2+concentration fixed at 0.5%-6%(at).In addition,emission bands of OC series samples peaked at 588 nm and 725 nm,were correspond-ing to the 4T1→6A1 transitions of Mn2+located at octahedral,and dodecahedral sites,respectively.The emission peak at 572 nm in the DO series was assigned to the transition of Mn2+occupying in distorted dodecahedral sites.Benefit-ing from the efficient energy transfer from Ce3+to Mn2+,the CRI and CCT of 70.8 and 5 117 K,respectively,were ac-quired from the white LD lighting device structured by YAG∶Ce3+phosphor ceramics with 6%(at)Mn2+occupying in octahedral site.This study presents a strong supplement to the research on Mn-doped garnet luminescent materials,and provides a reference for improving the color rendering performance of laser lighting sources by adding the red spectral component of YAG∶Ce3+phosphor ceramics,further driving their application in the field of medical treat-ment and display.
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