On the Ce3+→Cr3+ energy transfer in Lu3Al5O12 garnets

Two series of Lu3Al5O12:Cr3+ and Lu3Al5O12:0.5% Ce3+,Cr3+ luminescent materials were prepared by a sol–gel combustion method. All samples were characterized by powder X-ray diffraction (XRD), infrared (IR) and photoluminescence (PL) measurements. Moreover, luminous efficacies (LE), CIE 1931 colour points, and quantum efficiencies (QE) were calculated and discussed. Luminescence measurements indicated that Ce3+ ions located at Lu3+ site transfers absorbed energy to Cr3+ ions located at Al3+ site. However, with increasing Cr3+ concentration the total light output of Lu3Al5O12:0.5% Ce3+,Cr3+ phosphors decrease.