Synthesis of Ce³⁺ doped SrS nanocrystalline phosphors using a simple aqueous method

A simple aqueous method was used to synthesize a blue-green emitting Ce³⁺ doped SrS nanocrystalline phosphor. SrCl₂, Na₂S₂O₃ and Ce(NO₃)₃ were used as precursors for Sr²⁺, S^2- and Ce³⁺ ions respectively. Ethlylene diamine tetra acetic acid (EDTA) was used as a complexing agent. XRD studies revealed the single crystalline phase of the SrS:Ce³⁺. The morphology was examined using SEM and TEM and average particle size estimated from TEM images was 25 ± 2 nm in diameter. The elemental composition was analyzed with the electron dispersive x-ray spectroscopy (EDS). The photoluminescence (PL) study showed two emission peaks at 480 nm and 527 nm ascribed to the ²D(5d)→²F_5/2(4f) and ²D(5d)→ ²F_7/2(4f) transitions of the Ce³⁺ ion in SrS:Ce nanophosphors. These peaks are blue shifted from bulk SrS:Ce peaks at 485 nm and 530 nm. The intense emission peak at 480 nm at 254 nm excitation may be explored for possible applications in gamma and x-rays scintillators.