  Emerging technologies are demanding innovative properties of glasses. In this
work, Cerium Oxide is used as a dopant in Zinc-Tellurite samples and its
effects on the properties of the glass are investigated. Thermal analysis and
x-ray diffraction confirmed the amorphous nature of all samples. The bivalent
nature of Cerium is investigated spectroscopically and a strong redshift
induced by the dopant is attributed to charge transfers
O$^{2-}{\rightarrow}$Ce$^{4+}$, while the 4f-5d transition of Ce$^{3+}$ could
not be identified in absorption or luminescence measurements. Yellow/red
(570/650 nm) emission under 405/450 nm pumping were observed and are originated
from Te$^{4+}$ ions, which absorbs light in the UV/blue region of the spectrum.
The incorporation of some Cerium Oxide enhanced the visible luminescence,
though we found no evidence that Cerium ions play some role in the radiative
process. The luminescence is enhanced though due changes in the glass network
induced by the dopant.
