Synthesis and photoluminescence of Eu II in barium zinc orthosilicate: a novel green color emitting phosphor for white-LEDs

A series of Eu -activated barium orthosilicates (BaZnSiO ) were synthesized using a high-temperature solid-state reaction. A photoluminescence excitation study of Eu shows a broad absorption band in the range of 270-450 nm, with multiple absorption peak maxima (310, 350 and 400 nm) due to 4f-5d electronic transition. The emission spectra of all the compositions show green color emission (in the spectral region 450-550 nm with a peak maximum at 502 nm and a shoulder at ~ 490 nm) with appropriate Comission Internationale de l'Eclairage (CIE) color coordinates. The two emission peaks are due to the presence of Eu in two different Ba sites in the BaZnSiO host lattice. The energy transfers between the Eu ions in BaZnSiO host are elucidated from the critical concentration quenching data based on the electronic multipolar interaction. All Eu -activated BaZnSiO phosphor materials can be efficiently excited in the ultraviolet (UV) to near UV-region (270-420 nm), making them attractive candidate as a green phosphor for solid state lighting-white light-emitting diodes.