Structure and performance regulation of Mg2+,Zr4+co-doped ZnGa2O4:Cr3+-based near-infrared long persistent luminescence phosphors
XIAHOU Junqing
XU Siyi
LIU Xiangyu
XIE Wenlong
CAI Yanmei
LIU Yishui
XU Jieyu
CAO Li
ZHU Qi
LIU Zongming
Abstract：Objective To address the growing demands for excitation-free optical temperature sensing in modern engineering and anti-counterfeiting technologies,it is crucial to improve the persistent luminescence and optical temperature-sensing performance of near-infrared(NIR)long persistent luminescence phosphors,broadening their application scenarios.
Methods The ZnGa2-x(Mg-Zr)xO4:Cr3+(ZGMZC,x=0-0.2)NIR long persistent luminescence phosphors were synthesized via a high-temperature solid-state method by co-doping Mg2+and Zr4+into ZnGa2O4:Cr3+.A systematic analysis was conducted to investigate the effects of different Mg2+-Zr4+doping amounts on the phase structure,luminescence,and persistent luminescence performance of the ZnGa2O4system.Moreover,the material's potential for temperature sensing under natural light excitation was explored.
Results and Discussion The maximum doping amount of Mg2+-Zr4+was 10％.An increase in Mg2+-Zr4+doping content was obser-ved to enlarge the grain size while progressively widening the band gap.After high-temperature calcination,the samples exhib-ited strong capability for visible light absorption.The Mg2+-Zr4+doping facilitated the formation of anti-site defects,thereby increasing defects in the matrix.Consequently,the R-line emission and its Stokes and anti-Stokes phonon sidebands(PSB)gradually weakened in the emitted light,while the N-line emission gradually strengthened.However,excessive doping enhanced energy transfer between Cr3+and defects,which promoted more non-radiative transitions,causing energy loss and weakened luminescence.Furthermore,as the Mg2+-Zr4+doping amount rose,the sample's persistent luminescence initially increased and then decreased,with the x=0.05 sample exhibiting the optimal luminescence performance.Under dark conditions,the NIR per-sistent luminescence of the phosphors was enhanced with increasing temperature.
Conclusion The persistent luminescence performance of NIR phosphors is significantly enhanced through Mg2+-Zr4+co-doping.The synthesized materials exhibit temperature-dependent long persistent luminescence characteristics,which can be effectively charged under natural light and subsequently emit NIR light.The properties indicate their potential as natural light rechargeable materials for optical temperature sensing.
Keywords：near-infrared luminescencelong persistent luminescence phosphorsoptical temperature sensingperformance regulation
Publication Date：2025-09-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：12( 123-134 )