Synthesis and enhanced optical properties of Eu3+-doped β-Ga2O3 nanoparticles using Eu2O3@B2O3 core–shell

The enhancement of the red emission of Eu3+-doped β-Ga2O3 nanoparticles using Eu2O3@B2O3 core–shell structure as an activator were prepared as a function of the firing temperatures. The transmittance eletron microscope image and electron energy loss spectrum of the B2O3-coated Eu2O3 particles shows that the B2O3 coating is uniform, with a thickness of around 10 nm, and that the core–shell structure consisted of Eu and B elements. The X-ray diffraction patterns indicate that the Eu2O3@B2O3 (3 mol%)-doped β-Ga2O3 nanoparticles were indexed to the monoclinic crystalline β-Ga2O3. The broad absorption peaks at 1300 cm−1 (B–O bonds) disappeared in the patterns of the Eu2O3@B2O3 (3 mol%)-doped β-Ga2O3 nanoparticles prepared at 800 °C for 5 h, because of the evaporation of B2O3. The highest emission peaks of Eu2O3@B2O3 (3 mol%)-doped β-Ga2O3 nanoparticles were observed when prepared at 800 °C for 5 h. The Eu2O3@B2O3 core–shell structure used as an activator significantly enhanced the emission intensity compared with non-coated Eu2O3 doped β-Ga2O3 nanoparticles.

► The enhancement of the red emission of Eu3+-doped β-Ga2O3 nanoparticles using Eu2O3@B2O3 core–shell structure as an activator were prepared as a function of the firing temperatures.
► The liquid phase of B2O3 play an important role in improving optical property of the Eu2O3@B2O3 (3 mol%)-doped β-Ga2O3 nanoparticles.
► The highest red emission intensity of Eu2O3@B2O3 (3 mol%)-doped β-Ga2O3 nanoparticles was achieved at 800 °C for 5 h.