Infrared, visible and upconversion emission of CaAl12O19 powders doped with Er3+, Yb3+ and Mg2+ ions

Abstract

CaAl12O19 powders doped with Er3+, Yb3+, and Mg2+ ions have been prepared by a low-temperature combustion synthesis technique. Formation and chemical compositions were analysed by powder X-ray diffraction and energy-dispersive spectroscopy. The visible luminescence spectra of the doped phosphor upon excitation with similar to 378 nm radiation from a Xenon lamp have been studied. A broad band emission in the range of 1400-1700 nm with a peak around 1.5 A mu m and FWHM of about similar to 80 nm responsible for the eye-safe telecommunication window has been observed upon direct excitation with a NIR laser into the I-4(11/2) level of Er3+. The effect of co-doping with Yb3+ and Mg2+ ions in the CaAl12O19:Er3+ matrix on the photoluminescence intensity 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 of Er3+ is elaborated and discussed in detail.