Luminescent properties of Ce3+-doped Sr2MgSiO5 blue-emitting phosphor

The intense blue emitting phosphors Sr2MgSiO5 : Ce3+ were synthesized by high temperature solid state reaction method, and their luminescence properties were studied. The intense blue-emission band present a peak fixed at 420 nm, which consists of two peaks located at 408 and 445 nm, respectively. The two peaks are originated from the transition 5d ->(2) F-5/2 (4f) and 5d ->(2) F-7/2 (4f) of Ce3+ ions. The energy level difference value of the two emission bands is 2 038 cm(-1) which is consistent with the theoretic value(2 000 cm(-1)) between the ground state : F-2(5/2) and F-2(7/2) of Ce3+ ions. The excitation spectra extend from 250 to 400 nm and the peak positions around 365 nm. In addition, the effect of the concentration of Ce3+ ions and the role of charge compensation of different ions to the emission intense were investigated, the experiment results suggest that when the proportion of Ce3+ ions to Sr2MgSiO5 were 0.03 (molar ratio), the strongest emission was obtained. Li+, Na+ K+ and Cl- ions can all enhance the intensity of the emissions; especially Cl- ions gave the best improvement.