Structure, properties and luminescence mechanism of Sr1.93B2O5:0.07Eu3+ red phosphors

The Sr1.93B2O5:0.07Eu3+ phosphor was synthesized at 1050 °C for 2 h by high-temperature solid state reaction. The crystal structure, luminescent properties and luminescence mechanism were discussed. X-ray powder diffraction (XRD) analysis indicates that the crystal structure of Sr1.93B2O5:0.07Eu3+ phosphor is monoclinic Sr2B2O5. Spectra analysis indicate that phosphor demonstrate classic transition of Eu3+ ions except matrix absorption, the emission spectrum is composed of six emission peaks at 579 nm, 592 nm, 611 nm, 620 nm, 650 nm and 700 nm and the strongest emitting peak is at 611 nm originated from 5D0 → 7F2 electric dipole transition of Eu3+ ions, the excitation spectrum shows that phosphor can be excited by UV, near UV and blue light. It is found that Eu3+ ions occupy the center of asymmetrical octahedral polyhedron and form C2 point group. The Stokes frequency shift is 4568 cm−1 and the chromaticity coordinate of the Sr1.93B2O5:0.07Eu3+ phosphor is x = 0.524, y = 0.316. White LED with the phosphor and YAG:Ce3+ phosphor was prepared. The chromaticity coordinate of LED is x = 0.315, y = 0.359, and its irrelative color temperature is 6248 K. The phosphor can be used in white LED.