A New Red-Emitting La1–xPrxSr2AlO5 Phosphor Powder Prepared by Combustion Synthesis

Abstract

New red luminescent powders of La(1-x)Pr(x)Sr2AlO5 (x = 0.01 at.) were prepared by the combustion synthesis method. Microstructural properties were characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The La(1-x)Pr(x)Sr2AlO5 X-ray diffraction pattern revealed a tetragonal phase. Morphology of the grains showed nanobars with sizes of approximately 550 nm in length. Photoluminescence, cathodoluminescence and diffuse reflectance were analyzed in detail. Photoluminescence revealed two narrow emission peaks located at lambda(em1) = 497 nm (green) and lambda(em2) = 620 nm and a single maximum excitation peak of lambda(ex) = 287 nm. The cathodoluminescence spectrum confirmed the peaks detected by photoluminescence analysis. The absorbance spectrum showed broad absorption with a maximum around lambda = 280 nm, which agrees with the maximum excitation peak detected by photoluminescence.