Luminescent properties of Ca2SiO4:Eu3+ red phosphor for trichromatic white light emitting diodes

The luminescent properties of Eu3+doped Ca2SiO4 red phosphors synthesized by the flux fusion reaction method were investigated. It was found that the excitation spectrum included two regions: the weak excitation band below 325 nm and strong narrow peaks above 325 nm. The main peak of the excitation band was located at 400 nm. The peaks located at 290 nm were assigned to the combination of the charge transfer transition of O-Eu, peaks above 325 nm (325, 385, 400, 470, 511, and 539 nm) were assigned to the f–f transitions of Eu3+. The emission spectrum was dominated by the red peak located at 612 nm due to the electric dipole transition of 5D0–7F2. In addition, the effects of the Eu3+ content and charge compensators of Li+, Na+, K+, and Cl− ions on the emission intensity were investigated. The experiment results suggested that the strongest emission was obtained when the concentration of the Eu3+ ions was 0.3 mol−1, and Li+ ions gave the best improvement to enhance the emission intensity. Ca2SiO4:Eu3+, Li+ was thus suitable for low-cost trichromatic white light emitting diodes (WLED) based on UV InGaN chip.