Yb3+ mediated luminescence enhancement in Er3+ doped 3D-printed ZrO2 microarchitectures

Abstract

Lanthanide-doped ZrO2 ceramics are promising materials for optics due to their high refractive index and tunable luminescent properties. In this study, we investigated the impact of Yb3+ and Er3+ dopant concentrations on the emission behavior of lanthanide-doped 3D ZrO2 microarchitectures fabricated using two-photon lithography. Thermal treatments have been carried out at 600 degrees C and 750 degrees C to promote the stabilization of the ZrO2 tetragonal phase (t-ZrO2) and at 1000 degrees C to induce phase transition in ZrO2 to the monoclinic (m-ZrO2) phase in the 3D microarchitectures. Scanning transmission electron microscopy confirmed the crystallinity changes across the thermal treatments. Photoluminescence (PL) and cathodoluminescence (CL) measurements confirm emission bands of Yb3+ and Er3+ single dopants and Yb3+:Er3+ co-dopants. Variations in Yb3+ content reveal that the PL emission of Er3+ increases (e.g., 4S3/2 -> 4I15/2), which is attributed to the interplay between the dopant concentrations, defect structures and the ZrO2 host. The results highlight the importance of ZrO2microarchitectures' crystallinity and co-doping relationship, which enable the promotion of Er3+ emissions. We expect our research will find applications in 3D optical systems.