Simple and cost-effective method to obtain RE3+-doped Al2O3 for possible photonic applications

Abstract

Materials containing rare earth ions with photoluminescent properties have been investigated as efficient phosphors for applications in photonics. In this work We reports on preparation of Eu3+-doped Al2O3 with different concentrations of Eu3+, in relation to the amount of moles of Al3+, has been prepared using a simple and inexpensive synthesis. XRD showed that the alumina-based materials calcined at 400 and 600°C were predominated by the γ-Al2O3 phase. However the materials heat-treated above 800°C showed mixture of γ and α-Al2O3 phases. SEM presented results demonstrating that the heat-treatment at increased temperature favors a larger particle size with inhomogeneous morphology. It was observed with photoluminescence spectroscopy that theEu3+-doped Al2O3 materials showed intense photoluminescence emission around 612nm under excitation at 394nm. This emission in the visible region was assigned to a down-shifting phenomenon attributed to the intraconfigurational f-f transitions of Eu3+. Intense emission around 693nm assigned to Cr3+ were observed, and the intensity is controlled by the heat-treatment temperature of synthesis. The lifetime found for these materials are of the order of milliseconds at 612nm. In summary the materials obtained in this work show properties than can be used for photonics applications.