Development of luminescent materials with strong UV-blue absorption

A new green emitting phosphor Eu-activated orthoaluminate has been prepared by low temperature combustion synthesis of Eu-nitrate, A1-nitrate and a fuel (hydrazine). The crystalline structure was identified by X-ray diffraction and all the peaks could be indexed to the orthorhombic A1EuO(3) having a perovskite-type structure. A strong green-yellowish photholuminescence peak, centered at around 538 nm, was registered at room temperature when the phosphor was excited by ultraviolet photons in the range of lambda = 250-450 run due to electronic transitions generated in EU2+. This wide excitation range makes A1EuO(3):Eu2+, suitable for applications in solid state light devices, particularly at long UV wavelengths. Cathodoluminescent properties for the same phosphor powder were analyzed and produced a strong red peak centered at A = 616 run, which is typical of the hypersensitive D-5(o) -> F-7(2) transitions in EU3+. (c) 2004 Elsevier B.V. All rights reserved.