Achieving broadband near-infrared luminescence in Cr^(3+)-Activated Y_(2)Mg_(2)Al_(2)Si_(2)O_(12)phosphors via multi-site occupancy  

作　　者：Gui-Hua Li Han-Qi Wei Qi-Hua Yang Zhi-Wei Luo Ge-Mei Cai Li Ma Xiao-Jun Wang 

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]Science Center for Phase Diagram&Materials Design and Manufacture,Central South University,Changsha 410083,China [3]Department of Physics,Georgia Southern University,Statesboro,GA 30460,United States

出　　处：《Advanced Powder Materials》2024年第3期68-76,共9页先进粉体材料（英文）

基　　金：supported by the National Natural Science Foundation of China(No.51772330);the Fundamental Research Funds for the Central Universities of Central South University(No.506021713);the National MCF Energy R&D Program of China(No.2018YFE0306100).

摘　　要：Cr^(3+)-activated near-infrared(NIR)phosphors are key for NIR phosphor-converted light emitting diodes(NIR pc-LED).While,the site occupancy of Cr^(3+)is one of the debates that have plagued researchers.Herein,Y2Mg2Al2-Si_(2)O1_(2)(YMAS)with multiple cationic sites is chosen as host of Cr^(3+)to synthesize YMAS:xCr^(3+)phosphors.In YMAS,Cr^(3+)ions occupy simultaneously Al/SiO4 tetrahedral,Mg/AlO6 octahedral,and Y/MgO8 dodecahedral sites which form three luminescent centers named as Cr1,Cr2,and Cr3,respectively.Cr1 and Cr2 relate to an intermediate crystal field,with transitions of^(2)E→^(4)A_(2)and^(4)T_(2)→^(4)A_(2)occurring simultaneously.As Cr^(3+)concentration increases,the^(4)T_(2)→^(4)A_(2)transition becomes more pronounced in Cr1 and Cr2,resulting in a red-shift and broadband emission.Cr3 consistently behaves a weak crystal field and exhibits the broad and long-wavelength emission.Wide-range NIR emission centering at 745 nm is realized in YMAS:0.03Cr^(3+)phosphor.This phosphor has high internal quantum efficiency(IQE?86%)and satisfying luminescence thermal stability(I423 K?70.2%).Using this phosphor,NIR pc-LEDs with 56.6 mW@320 mA optical output power is packaged and applied.Present study not only demonstrates the Cr^(3+)multi-site occupancy in a certain oxide but also provides a reliable approach via choosing a host with diverse cationic sites and local environments for Cr^(3+)to achieve broadband NIR phosphors.

关 键 词：Near-infrared phosphor pc-LEDs Cr^(3+) Broadband emission Site occupancy Crystal field 

分 类 号：O61[理学—无机化学]