Soft-Chemistry Derived Advanced Phosphors for Smart Lighting Devices Based on Blue or UV LEDs

Abstract

This work deals with phosphors suitable for applications in a new generation of Hg-free lamps based on deep ultraviolet (DUV), ultraviolet (UV) and blue light emitting diodes (LEDs). First, two synthesis routes, solid state reaction and Pechini method, have been used for preparing an original red phosphor, Y3BO6:Eu3+. Phase purity was confirmed by XRD analysis for Pechini derived sample after washing the powder with an acidic solution while the synthesis dependence of the morphological and optical characteristics was evidenced by SEM analysis and photoluminescence respectively. Y3BO6:Eu3+ powders derived from Pechini process exhibited high photoluminescence quantum efficiency upon excitation at wavelengths corresponding to afore mentioned sources, in comparison with commercial Y2O3:Eu3+ red phosphor. Furthermore, the Pechini method was used for elaborating Y3BO6:Eu3+ spray-coated thin film. Its structural and optical features were also investigated. Finally, colorimetric simulations have pointed out that Y3BO6:Eu3+ could be efficiently combined with blue and green phosphors to produce white light from DUV LEDs. Regarding blue LEDs sources, a mixture constituted of Y3Al5O12:Ce3+ and Y3Al5O12:Pr3+ powders has been investigated and resulted in promising results for providing white light with suitable features for indoor or outdoor lighting.