Luminescent properties of Al2O3:Tb3+ nanoparticles obtained by cw CO2 laser vaporization.

The synthesis of Al 2 O 3 :Tb3+ (0.019–0.62 mol%) nanoparticles by laser vaporization of α-Al 2 O 3 :Tb3+ ceramic targets using a cw CO 2 laser in flowing helium at a pressure of 0.1 bar is reported. HRTEM, XRD and BET studies revealed that under the indicated conditions the produced Al 2 O 3 :Tb3+ nanoparticles have faceted and nearly a spherical shape with the average size below 10 nm. As shown by XRD, the phase composition of the synthesized nanoparticles is represented mostly by the low-temperature γ-Al 2 O 3. Photoluminescence (PL) spectra were obtained for Tb3+ ions in γ-Al 2 O 3 nanoparticles upon excitation to the 4f8 → 4f75d (λ ex = 230 nm), 7F 6 → 5H 7 (λ ex = 315 nm) and 5D 3 → 7F 3 (λ ex = 458 nm) transitions, and PL excitation spectra – for the most intense 5D 4 → 7F 5 (λ max = 543 nm) transition. The lifetime of the excited 5D 4 state was found to be ca. 2.9 ms. The obtained values of the chromaticity coordinate and absolute quantum yield were (0.299, 0.509) and 12.6% at λ ex = 315 nm, respectively. • Terbium doped Al 2 O 3 nanoparticles were obtained via laser vaporization. • Al 2 O 3 :Tb3+ nanophosphor with photoluminescent properties was achieved. • CIE coordinates and high QY are suitable for use Al 2 O 3 :Tb3+ as a green phosphor. [ABSTRACT FROM AUTHOR]