Transparent rare earth‐doped gallium oxide ceramics with oriented microstructure

Gallium oxide (Ga 2 O 3 ) has attracted much attention due to its promising applications in optical and electronic devices, while it is difficult to fabricate high‐quality Ga 2 O 3 transparent ceramics because of the non‐cubic crystal structure. In this work, fully densified undoped and rare earth (RE = Tb, Dy. Er)‐doped Ga 2 O 3 transparent ceramics were successfully fabricated by using spark plasma sintering (SPS) and co‐precipitated ceramic powders. Both the powders and ceramics showed pure monoclinic β ‐ Ga 2 O 3 crystal structure and unique orientation. After sintering by SPS for 30 min, all the ceramics reached a relative density higher than 99.21%. The total transmittance of RE‐doped Ga 2 O 3 transparent ceramics ranges from 60% to 69% originating from the oriented and dense microstructures. The photoluminescence spectra and fluorescence lifetime of RE‐doped Ga 2 O 3 transparent ceramics confirm characteristics of energy transfers corresponding to Tb 3+ , Dy 3+ , or Er 3+ ions in the visible and NIR spectral region. This study demonstrates that oriented RE‐doped Ga 2 O 3 transparent ceramics have great potential to be used in various optical applications.