Characterizations of Ba(Y1−xEux)2ZnO5 (x = 0–0.4) phosphor synthesized via a sol–gel process

A color-tunable Eu3+ ion-doped BaY2ZnO5 phosphor prepared by adjusting the Eu3+ ion concentration has been synthesized using the sol–gel method. Under an excitation of 395 nm, the color tone of BaY2ZnO5:Eu3+ phosphor changes from blue through white, and finally to red with increasing Eu3+ ion concentration. The Ba(Y1−xEux)2ZnO5 phosphor emits red luminescence when the x is higher than 0.2, and has the strongest emission intensity when the x is 0.25. The red emission of the BaY1.2Eu0.8ZnO5 phosphor has CIE chromaticity coordinates of (0.66, 0.33), which is very close to the NTSC system standard red chromaticity (0.67, 0.33). Compared to the solid state reaction, emission intensity for the 5D0 → 7F2 transitions of BaY1.6Eu0.4ZnO5 phosphor was about 4.2 times higher for the sol–gel method. The critical concentration (xc) and critical distance (Rc) are 0.5 and 7.81 Å, respectively, and those are larger than those prepared using solid state reaction.