Sensitization of Er3+/Ho3+ visible and NIR emission in NaY(MoO4)2 phosphors

[Display omitted] •NaY(MoO4)2 doped Er3+ and Ho3+ synthesized by conventional solid state reaction.•Intense visible and NIR emissions from Er3+ and Ho3+ are observed.•The emissions are sensitization by from the MoO42− group.•The possible energy transfer mechanisms are discussed. Efficient, host-sensitized, visible and near-infrared emitting phosphors NaY(MoO4)2, doped with Ln3+ (Ln = Er and Ho) were synthesized by a conventional solid state reaction and characterized with X-ray diffraction, photoluminescence emission and excitation spectra. Rietveld refinement was performed to investigate the phase purity of the NaY(MoO4)2 samples. Sensitization of Ln3+ (Ln = Er and Ho) from the host with different doping concentrations of Ln3+ were investigated. Under excitation at 310 nm, the phosphor gives intense and characteristic emission of Er3+ and Ho3+ in both the visible and NIR region due to sensitization by MoO42− group. In the excitation spectra there is a broad band ranging from 250 to 380 nm which is associated with the O2−-Mo6+ charge transfer transition in the MoO42− group. An efficient energy transfer from MoO42− to Er3+ and MoO42− to Ho3+ is observed. The interesting luminescence properties highlight the significance of Er3+/Ho3+ doped NaY(MoO4)2 phosphor for their use in optical and photonic devices.