Wide visible-range fluorescence of Eu(3+) located in the macroscopic bi-layer ceramic/glass composite

The Eu(3+) doped fluoride bi-layer ceramic/glass composite (GC(ZBL)-Eu) was prepared by a one-step method and the effective wide visible-range fluorescence was recorded. The de-population rates of the (5)D(0), (5)D(1), (5)D(2), and (5)D(3) multi-levels in the glass layer (G(ZBL)-Eu) were estimated to be 214, 746, 1163, and 680 s(−1), respectively, and that in the ceramic layer (C(ZBL)-Eu) were 211, 730, 1075, and 654 s(−1), which implies multi-channel radiative transitions due to the non-radiative relaxation limitation of low OH content and low phonon energy. Simultaneously, the quantum efficiencies of the (5)D(0) levels in G(ZBL)-Eu and C(ZBL)-Eu were as high as 98.5% and 94.8%, respectively, thus demonstrating the effectiveness of the radiative transition emissions from Eu(3+). Besides, GC(ZBL)-Eu with the glass forming layer increases the emission intensity by 24% compared to C(ZBL)-Eu, which is attributed to the multiple-cycle reflection in the composite structure of the glass–ceramic transition region, and the color coordinates of C(ZBL)-Eu (0.483, 0.385) and GC(ZBL)-Eu (0.469, 0.389) show that they can release yellowish-white light. The hetero-structured GC(ZBL)-Eu provides a new approach for laser lighting, fluorescent display, and up-conversion applications.