The concentration effect of upconversion luminescence properties in Er3+/Yb3+-codoped Y2(MoO4)3 phosphors

Y2(MoO4)3:Er3+/Yb3+ phosphors with fixed (varied) Er3+ and varied (fixed) Yb3+ concentrations were synthesized by a conventional solid-state reaction. The crystal structure of the phosphors was characterized by means of X-ray diffraction (XRD). Upon 980 nm excitation, very weak blue emission, and strong green and red upconversion emissions centered at 485, 525, 545 and 656 nm were observed. The two-photon process was confirmed to be responsible for both the green and red upconversion emissions. The effects of green upconversion emission intensity ratio (2H11/2→4I15/2 versus 4S3/2→4I15/2) and the integrated upconversion emission intensity on the Yb3+ and Er3+ concentrations were studied.