Formation and down/up conversion luminescence of Ln3+ doped NaY(MoO4)2 microcrystals†
Abstract
NaY(MoO4)2 microcrystals with different morphologies including spherical, rhombic, sheet-like, and rectangular plate-like morphologies have been successfully synthesized via a simple hydrothermal method by varying the molar ratios of Y(NO3)3/Na2MoO4 and pH values of the resultant solutions. NaY(MoO4)2 was demonstrated to be a good host material for different lanthanide ions. In the up-conversion luminescence spectrum of NaY(MoO4)2:Yb3+/Er3+ under 980 nm excitation, the green emissions (2H11/2/4S3/2 → 4I15/2) were observed and the red emission (4F9/2 → 4I15/2) almost disappeared. The CIE chromaticity coordinates of NaY(MoO4)2:Yb3+/Er3+ were calculated to be (0.27, 0.65). In the up-conversion luminescence spectrum of NaY(MoO4)2:Yb3+/Tm3+, the 1G4 → 3H6 as well as 3F3 → 3H6 emission was observed and the CIE chromaticity coordinates of NaY(MoO4)2:Yb3+/Tm3+ were calculated to be (0.25, 0.24). The down-conversion luminescence properties of NaY(MoO4)2:Eu3+ were studied in detail. In addition, the decay lifetimes at the 4S3/2 (Er3+), 1G4 (Tm3+), and 5D0 (Eu3+) states were determined to be 5.63 μs, 19.76 μs, and 487.39 μs, respectively.