Eu3+-doped NaYGeO4: A novel red-emitting phosphors for ultraviolet or blue chips excited white LEDs

A novel red-emitting phosphor NaYGeO4: Eu3+ has been prepared by a high temperature solid state method. All the Eu3+ ions are completely dissolved in the NaYGeO4 host without changing its crystal structure. Under 315 nm host excitation or 464 nm F-7(0) -> D-5(2) excitation, the phosphor NaYGeO4: Eu3+ presents red emission with the strongest peak at 613 nm. The concentration quenching and luminescence mechanism are also investigated. The optimal NaYGeO4: 0.05Eu(3+) phosphor displays high internal quantum efficiency, excellent thermal stability with the activation energy (Delta E) of 0.2716 eV. The color emission can be tuned by changing the Eu3+ concentration. The phosphor presents a great potential application for ultraviolet or blue excited white LED.