Synthesis and luminescence properties of Sm3+-doped La2WyMo2−yO9 orange-red phosphors

La2WyMo2−yO9 phosphors activated with the trivalent rare-earth Sm3+ were synthesized via a traditional solid-state reaction, their structure and luminescence properties were investigated by using X-ray diffractometer and fluorescence spectrophotometer. There were three emission peaks centered at 563, 599, and 646 nm corresponding to the 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2 transitions of Sm3+ under the 402 nm ultraviolet excitation. Investigation on Sm3+ concentration-dependent emission spectra indicated that La1.97WMoO9:3% Sm3+ phosphor exhibited the strongest orange-red emission with a CIE value of (0.5425, 0.4541). Therefore, it is considered to be a new promising orange-red emitting phosphor for white light emitting diode (LED) application.