LAUSR

Abstract The synthesis of Al2O3:Tb3+ (0.019–0.62 mol%) nanoparticles by laser vaporization of α-Al2O3:Tb3+ ceramic targets using a cw CO2 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 Al2O3: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-Al2O3. Photoluminescence (PL) spectra were obtained for Tb3+ ions in γ-Al2O3 nanoparticles upon excitation to the 4f8 → 4f75d (λex = 230 nm), 7F6 → 5H7 (λex = 315 nm) and 5D3 → 7F3 (λex = 458 nm) transitions, and PL excitation spectra – for the most intense 5D4 → 7F5 (λmax = 543 nm) transition. The lifetime of the excited 5D4 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 λex = 315 nm, respectively.