Shi Haifeng, Yang Jiaxin, Yu Zhimin, Song Yu, Bun Pun Edwin Yue, Zhao Xin, Lin Hai
School of Textile and Material Engineering, Dalian Polytechnic University Dalian 116034 P. R. China
Department of Electronical Engineering and State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P. R. China.
RSC Adv. 2020 May 21;10(33):19474-19481. doi: 10.1039/d0ra01236j. eCollection 2020 May 20.
The Eu doped fluoride bi-layer ceramic/glass composite (GC-Eu) was prepared by a one-step method and the effective wide visible-range fluorescence was recorded. The de-population rates of the D, D, D, and D multi-levels in the glass layer (G-Eu) were estimated to be 214, 746, 1163, and 680 s, respectively, and that in the ceramic layer (C-Eu) were 211, 730, 1075, and 654 s, 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 D levels in G-Eu and C-Eu were as high as 98.5% and 94.8%, respectively, thus demonstrating the effectiveness of the radiative transition emissions from Eu. Besides, GC-Eu with the glass forming layer increases the emission intensity by 24% compared to C-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-Eu (0.483, 0.385) and GC-Eu (0.469, 0.389) show that they can release yellowish-white light. The hetero-structured GC-Eu provides a new approach for laser lighting, fluorescent display, and up-conversion applications.
采用一步法制备了铕掺杂氟化物双层陶瓷/玻璃复合材料（GC-Eu），并记录到了有效的宽可见范围荧光。玻璃层（G-Eu）中D、D、D和D多能级的去激发速率分别估计为214、746、1163和680 s⁻¹，陶瓷层（C-Eu）中的去激发速率分别为211、730、1075和654 s⁻¹，这意味着由于低OH含量和低声子能量的非辐射弛豫限制导致了多通道辐射跃迁。同时，G-Eu和C-Eu中D能级的量子效率分别高达98.5%和94.8%，从而证明了铕的辐射跃迁发射的有效性。此外，与C-Eu相比，具有玻璃形成层的GC-Eu的发射强度提高了24%，这归因于玻璃-陶瓷过渡区域复合结构中的多循环反射，C-Eu（0.483，0.385）和GC-Eu（0.469，0.389）的色坐标表明它们可以发出黄白色光。这种异质结构的GC-Eu为激光照明、荧光显示和上转换应用提供了一种新方法。
