Visible upconversion and infrared luminescence investigations of Al2O3 powders doped with Er3+, Yb3+ and Zn2+ ions

Abstract

Alumina (Al2O3) powders doped with Er3+, Yb3+ and Zn2+ ions have been prepared by a low-temperature combustion synthesis technique. The phase purity and crystalline structure of the combustion products are confirmed by powder X-ray diffraction. An efficient frequency upconversion in the visible region and the emission in the infrared (IR) region respectively corresponding to the H-2(11/2), S-4(3/2)-> I-4(15/2), F-4(9/2)-> I-4(15/2) and I-4(13/2)-> I-4(15/2) transitions upon direct excitation with a CW laser lasing at similar to 980 nm are discussed. The enhancement observed in the intensity of the upconversion emission bands in the visible region and the emission band in the IR region due to the presence of Yb3+ and Zn2+ in Er3+:Al2O3 powders is reported and explained in detail.