Bi3+-Sensitized La2Zr2O7:Er3+ Transparent Ceramics with Efficient Up/Down-Conversion Luminescence Properties for Photonic Applications
journal contributionposted on 26.12.2019, 14:35 by Dan Ruan, Zhangyi Huang, Zhe Tang, Yutong Zhang, Xiuling Wang, Mao Zhou, Jianqi Qi, Tiecheng Lu
Optical gain materials are of great importance for photonic applications, particularly in the realization of high-performance lasers and amplifiers. Unfortunately, the relatively poor thermodynamic stability greatly restricts their applications in harsh environments. Here, promising gain materials with harsh-environment endurance, transparent La2Zr2O7:Er3+,Bi3+ (LZO:Er,Bi) ceramics, were fabricated successfully. The LZO:1% Er,2% Bi ceramics exhibit the highest in-line transmittance of 64.8% at 1300 nm. Enhanced photoluminescence from Er3+-doped LZO sensitized with Bi3+ has been observed. We systematically study the sensitization mechanism of Bi–Er coupling from both up- and down-conversion. The former originates from the energy back-transfer and the modification of the symmetry of the crystal field in the lattice, where the modification of the crystal field is dominant during an up-conversion sensitized process. The latter is attributed to the efficient energy transfer (ET) from Bi3+ to Er3+. The calculated ET efficiency ηET is about 72%. The most probable ET mechanism from Bi3+ to Er3+ in LZO ceramics is the dipole–dipole interaction. The LZO:Er,Bi transparent ceramics with excellent thermal stability, effective luminescence, and a long metastable-level lifetime can be potential candidates as optical gain materials for photonic applications in severe environments.