Color-conversion and photoluminescence properties of Ba sub(2MgW(Mo)O) sub(6):Eu phosphor

Compounds B sub(2AXO) sub(6):Eu (B = Ba, Sr; A = Ca; and X = W, Mo) have recently been investigated and suggested to be color-conversion phosphor for WLED devices. In this work, we investigated the photoluminescence properties of the analogues Ba sub(2MgXO) sub(6):Eu (X = W and Mo) and the energy transfer from W(Mo)O sub(6 groups to Eu) super(3)+ ions within the phosphors. The phase structure, UV-vis diffuse reflectance spectrum, photoluminescence properties and decay of Ba sub(2MgW) sub(()1-x)Mo sub(xO) sub(6):Eu were studied as a function of the W/Mo ratio. It was found that these phosphors showed excellent color-conversion capability from near-UV to orange-red light. The color-conversion process was considered to be performed by energy transferring from MoO sub(6 groups to doped Eu) super(3)+ ions. The MoO sub(6 -- Eu) super(3)+ energy transfer efficiency could be greatly enhanced by partial substitution of Mo by W. The structure and photoluminescence properties of Ba sub(2AW) sub(0).5Mo sub(0.5O) sub(6):Eu (A = Ca and Mg, respectively) compounds were also investigated to reveal the effect of the Eu super(3+ ion coordination environment on its photoluminescence properties.)