Multicolor light emission in Dy3+/Tb3+-codoped LaF3 nanocrystals under UV excitation

Multicolor light emission and energy-transfer processes were examined in Dy3+/Tb3+-codoped LaF3 nanocrystals. The phosphor was synthesized, and the light emission feature was examined under UV (375 and 385 nm) excitation. Emission around 484, 573, 663, and 754 nm due to dysprosium and 488, 545, 585, 620, and 690 nm owing to terbium ions was observed and analyzed as a function of the dysprosium and terbium contents and excitation wavelength. A dysprosium-terbium energy-transfer process was also observed and analyzed. The excitation spectrum was examined and showed resonances around 385 nm for the Dy (573 nm emission) and 375 nm for the Tb (540 nm emission). Results indicate that the polychromatic light-emitting phosphor Dy3+/Tb3+-codoped LaF3 nanocrystals herein reported generated light with a color tone tunable either by excitation wavelength or active ions content and suggest that it is a promising contender for LED-based illumination.