Preparation and optical properties of YH₂:Er²⁺ and Y₂O₃:Er³⁺ nanoparticles

The rare earth hydride nanoparticles have been prepared successfully by a novel method of hydrogen plasma-metal reaction. The YH₂:Er ²⁺ nanoparticles of 40-50 nm were polycrystalline and in hexagonal shape. The Y₂O₃:Er³⁺ nanoparticles were fabricated by annealing the hydride nanoparticles in air at 300, 500 and 700 °C, respectively. The influence of the sintering temperature on the size, crystal structure and optical properties of these nanoparticle samples were investigated. After annealing, the Y₂O₃:Er³⁺ nanoparticles became single crystalline and spherical shape, and the mean particle size of these particles did not change apparently upon the annealing temperature up to 700 °C. With the increase of the annealing temperature, the absorption intensity of YH₂ in the Fourier transform infrared spectroscopy spectra decreased and the peak position moved to highfrequency, whereas the absorption intensity of Y₂O₃ was enhanced. The intensity of the near-IR fluorescence spectra of the Y₂O ₃:Er³⁺ nanoparticles increased remarkably with the increase of the annealing temperature from 300 to 700 °C. The Y ₂O₃:Er³⁺ sample sintered at 700 °C exhibited a strong photoluminescent intensity at the wavelength of about 1535 nm, with a narrow full width of 6 nm at the half maximum. This makes the Y ₂O₃:Er³⁺ nanoparticles promising for the applications in the optical communication devices.