Investigations of the effect of trivalent erbium concentration on orthophosphate powder for green and yellow-orange light emitting phosphor.

Lately, interesting features of lighting Rare Earths doped phosphorus have gained much attention and became favorite research matter among various groups of scientists. In this context, polycrystalline powders of Na 3 La(PO 4) 2 : Er (0%, 2,5%) have been prepared by the solid state method. Powder X-ray diffraction, infrared spectroscopy have been used to identify these materials. The spectroscopic properties of Na 3 La(PO 4) 2 : Er (2,5%) have been investigated through absorption, excitation, emission spectra and decay curves of Er3+ at room temperature. The decay time reveal that Na 3 La(PO 4) 2 : Er (2,5%) possesses a radiative transition and the lifetime value for the transition 4F 9/2 → 4I 15/2 is found equal to 144.92 μs. All obtained results have been presented, compared and discussed with last reported works. The CIE chromaticity coordinates have been highlighted. They reveal that Na 3 La(PO 4) 2 : Er (2,5%, 10%, 20% and 50%) phosphor can be a promising green and yellow-orange luminophore for application in LED. [ABSTRACT FROM AUTHOR]