A potential single-phased emission-tunable silicate phosphor Ca3Si2O7:Ce3+,Eu2+ excited by ultraviolet light for white light emitting diodes

Single-phased Ca3Si2O7:Ce3+,Eu2+ phosphor has been successfully prepared by the high temperature solid-state method. The phosphor shows efficient excitation bands from 200 to 400 nm and adjustable emission bands through the energy transfer from the Ce3+ to Eu2+ ions. The color hues can change from blue towards white ultimately to orange by adjusting the percentage content of doping ions. The investigation reveals that an electric dipole–dipole reaction mechanism should be responsible for the energy transfer from the Ce3+ to Eu2+ ions. The critical distance was obtained from the spectral overlap in terms of Dexter’s theory. The developed phosphor Ca3Si2O7:Ce3+,Eu2+ exhibits two bands at 440 and 625 nm, respectively, which reveling that it has a great potentiality to be an UV-convertible phosphor for white-light emitting diodes with low color temperature.

► The luminescent properties of the obtained phosphors have efficient excitation bands from 200 to 400 nm.
► The color hues can change from blue to white ultimately to orange by tuning the percentage content of the doping ions.
► A reasonable approximation of the actual crystal structure as a starting model has been built to perform the refinement.
► The luminescence properties, energy transfer mechanism and critical distance have been investigated.