Photoluminescence properties of the ZnO-CdO-TeO2 system doped with the Tb3+and Yb3+ ions

ZnO-CdO-TeO2 was employed as a host of Tb3+ and Yb3+ ions. The matrix doped with Tb3+ presents a crystalline/amorphous structure, while the same matrix shows an amorphous structure when it is doped with Yb3+. Optical absorption spectra, measured by using photoacoustic (PA) spectroscopy, allowed to determine the band gap, which is localized in the range 3.47-3.60 eV. Both kinds of ions Tb3+ and Yb3+ in the ZnO-CdO-TeO2 matrix show emissions that are characteristic of such ions. For Tb3+ the signals were allocated in 548, 586, 622 nm, respectively, while for Yb3+ only one signal was registered at 1000 nm.