Spectroscopic Study Of Er3+-Doped Zinc-Tellurite Glass And Opaque Glass-Ceramic

Er3+-doped zinc tellurite glass and glass-ceramic are prepared by simple melt-quenching technique and subsequent heat-treatments at two defined crystallization temperatures. The heat-treated sample at 460 degrees C converts to an opaque glass-ceramic with the formation of mainly Zn2Te3O8 and TeO2 crystalline phases. There is no peak observed corresponding to the ZnTeO3 phase. The effective bandwidth of the near-infrared emission band of Er3+ ions at around 1.5 mu m increases from 65 nm to 89 nm after exposing the sample to heat-treatment owing to the formation of different symmetry sites around Er3+ ions. The lifetime of this band decreases from 2.49 to 1.72 ms. The upconversion emission bands in ceramized sample show a red-shift, while the green to red upconversion intensity ratio decreases from 3 to 0.6, respectively, for glass and glass-ceramic samples. The mechanism behind this observation is discussed by possible energy transfer between Er3+ ions in the crystalline phase.