High Efficiency Nitride Based Phosphors for White LEDs

Abstract

In this overview paper, novel rare-earth doped silicon nitride based phosphors for white LEDs applications have been demonstrated. The luminescence properties of orange-red-emitting phosphors (M₂Si₅N₈:Eu²⁺) and green-to-yellow emitting phosphors (MSi₂N₂O₂:Eu²⁺, M = Ca, Sr, Ba) are discussed in detail with a focus on the relationship between the properties and structures. With high conversion efficiency in the near UV/blue region, along with high chemical/physical stability, Eu²⁺ - and Ce³⁺ - activated alkaline-earth silicon nitride and oxynitride materials are excellent wavelength-conversion phosphors for white LEDs.