Tunable photoluminescence properties of Sr 1‐y Ca y MoO 4 :Sm 3+ phosphors (0 ≤ y < 1)

A series of Sr 1‐x‐y Ca y MoO 4 :xSm 3+ (0 ≤ x ≤ 7 mol% and 0 ≤ y < 1) phosphors was synthesized by a conventional solid‐state reaction method in air, and their structural and spectroscopic properties were investigated. The optimal doping concentration of Sm 3+ in SrMoO 4 :Sm 3+ phosphor is 5 mol%. Under excitation with 275 nm, in Sr 1‐x‐y Ca y MoO 4 :xSm 3+ (0 ≤ x ≤ 7 mol% and 0 ≤ y < 1) phosphors, the emission band of the host was found to overlap with the excitation bands peaking at ~500 nm of Sm 3+ ion, and the energy transfer from MoO 4 2− group to Sm 3+ ion can also be observed. The International Commission on Illumination (CIE) chromaticity coordinates of Sr 0.95‐y Ca y MoO 4 :0.05Sm 3+ phosphors with excitation 275 nm varied systematically from an orange (0.4961, 0.3761) (y = 0) to a white color (0.33, 0.3442) (y = 0.95) with increasing calcium oxide (CaO) concentration. However, Sr 0.95‐y Ca y MoO 4 :0.05Sm 3+ phosphors with excitation at 404 nm only showed red emission and the energy transfer between MoO 4 2− group to Sm 3+ ion was not observed. The complex mechanisms of luminescence and energy transfer are discussed by energy level diagrams of MoO 4 2− group and Sm 3+ ion. Copyright © 2015 John Wiley & Sons, Ltd.