Wavelength conversion of Yb3+-activated Y4CdMo3O16 from near UV-region to IR emission

Yb3+ (0.5-30 mol %) activated Y4CdMo3O16 phosphors have been prepared by the traditional solid-state reaction method. The phase formation was investigated by the XRD structural refinements. The surface properties of the powder phosphors were verified by SEM, TEM and EDS measurements. The optical properties were evaluated by the reflectance spectra, photoluminescence excitation and emission spectra, decay curves (lifetimes), and the absolute quantum efficiency (QE). Under the excitation of UV light, Yb3+-activated Y4CdMo3O16 shows the efficient near-infrared (NIR) emission bands (900-1100 nm), which is ascribed to the 2F5/2 → 2F7/2 transitions of Yb3+ ions. The NIR emission intensity shows a dependence on Yb3+ contents, which has an optimal doping of 25 mol %. The energy transfer (ET) from MoO4 to Yb3+ ions in the lattices was discussed. The NIR emission around 1000 nm just corresponds to the optical response of Si-based solar cells. Consequently, the efficiency could be enhanced by arranging luminescent layers mixed with Y4CdMo3O16:Yb3+ phosphors and transparent matrix in the front surface of Si solar cells.