Analysis of europium doped luminescent barium thioaluminate

Europium-doped barium thioaluminate sputtering target was synthesized by powder sintering method and thin film was deposited by radio frequency (RF) sputtering. X-ray diffractometer (XRD) pattern indicated that the main compound of the target was BaAl4S7. Oxygen was the main impurity which led to the formation of BaAl2O4. It was shown that both BaAl4S7 and BaAl2S4 were contained in the as-grown thin films and a 471.7 nm emission peak in the PL spectra appeared due to a combination of BaAl4S7:Eu2+ and BaAl2S4:Eu2+. In addition, the product of oxidation in the film was BaSO4 instead of BaAl2O4 and led to an emission peak at 415.2 nm in the PL spectra assigned to the f→f transition of Eu2+ in the BaSO4 host.