Room temperature synthesis of highly luminescent Eu3+ and Tb3+-doped hexagonal-phase YPO4 nanoparticles with tunable emission

Abstract

Luminescent lanthanide nanoparticles are usually prepared at high temperatures, which makes these materials costly. Here, we are preparing one such material in a simple way at room temperature. We were able to prepare green and red emissive nanoparticles from Tb³⁺ and Eu³⁺ doped YPO₄ hexagonal phase nanoparticles. Tb³⁺ to Eu³⁺ energy transfer also occurs and by varying their ratio we tuned the emission color from green to yellow to red. We were able to increase the quantum yield 10-fold by doping Li⁺ ions into this system, while still maintaining the h-phase, even though this phase is reported to be less emissive.