Optical Properties of Red-Emitting Rb(2)Bi(PO(4))(MoO(4)):Eu(3+) Powders and Ceramics with High Quantum Efficiency for White LEDs

There are several key requirements that a very good LED phosphor should meet, i.e., strong absorption, high quantum efficiency, high colour purity, and high luminescence quenching temperature. The reported Rb(2)Bi(PO(4))(MoO(4)):Eu(3+) phosphors have all these properties. The Rb(2)Bi(PO(4))(MoO(4)):Eu(3+) phosphors emit bright red light if excited with near-UV radiation. The calculated colour coordinates show good stability in the 77–500 K temperature range. Moreover, sample doped with 50% Eu(3+) possesses quantum efficiency close to unity. Besides the powder samples, ceramic disks of Rb(2)Eu(PO(4))(MoO(4)) specimen were also prepared, and the red light sources from these disks in combination with near-UV emitting LED were fabricated. The obtained results indicated that ceramic disks efficiently absorb the emission of 375 and 400 nm LED and could be applied as a red component in phosphor-converted white LEDs.