The synthesis and luminescence properties of a novel red-emitting phosphor: Eu-doped CaLa(PO).

A series of novel red-emitting phosphors CaLa(PO): xEu were synthesized by high-temperature solid state reactions. The photoluminescence excitation and photoluminescence spectra of these phosphors were investigated in detail. O-Eu charge transfer band peaking at about 261 nm is dominant in the PLE spectra of Eu-doped CaLa(PO), indicating that the phosphors are suitable for tricolor fluorescent lamps. The phosphors also show a good absorption in near ultraviolet (around 395 nm) and blue (around 465 nm) spectral region, which indicates that it can be pumped with NUV and blue chips for white light-emitting diodes. The transition of D → F of Eu in this lattice can emit bright red light. CaLa(PO) could accommodate a large amount of Eu with an optimal concentration of 60 mol%. The dipole-dipole interaction between Eu is the dominant mechanism for concentration quenching of Eu. The calculated color coordinates lie in red region ( x = 0.64, y = 0.36), which is close to YO: 0.05Eu ( x = 0.65, y = 0.34). The integral emission intensity of CaLa(PO): 0.6Eu is 1.9 times stronger than that of widely used commercial red phosphor YO: 0.05Eu. All these results indicate that Eu-doped CaLa(PO) is a promising red-emitting phosphor which can be used in tricolor fluorescent lamps and white light-emitting diodes . [ABSTRACT FROM AUTHOR]