Synthesis and luminescence properties of a novel red-emitting phosphor SrCaSiO4:Eu3+ for ultraviolet white light-emitting diodes

A novel red phosphor based on Eu3+-activated SrCaSiO4 was successfully synthesized by conventional solid state reaction method and the photoluminescence properties were investigated. X-ray diffraction (XRD) patterns indicated that SrCaSiO4:Eu3+ phosphors belong to orthorhombic crystal system (space group=Pmnb). The photoluminescence (PL) excitation spectrum showed broad-band absorption and the strongest excitation peak at 397 nm contributed to the F-7(0)-> L-5(6) transition which matched well with the emission of a UV chip. The PL emission spectrum with the peaks at 577, 586, 592, 612, 650 and 685 nm, were probably attributed to the transitions from D-5(0) to F-7(J)(J=0, 1, 2, 3, 4) of Eu3+ ions. The quenching concentration of Eu3+ was 10 mol.%, and the critical distance (R-c) was about 1.2 nm. The fluorescence lifetime of Eu3+ ions was found to be 3.2 ms. The results indicated that the SrCaSiO4:Eu3+ might become an important red phosphor candidate for white-light-emitting diodes with near-UV LED chips.