Er3+/Yb3+ ions in a novel zinc borate glass: spectroscopic and physical properties

Novel zinc borate glass doped with mixed rare-earth ions such as erbium (Er3+) and ytterbium (Yb3+) ions were prepared by conventional melt annealing process. The structural glass network comprised units of ZnO4, triangle borate (BO3), tetraborate (BO4), and B-O-B and B-O-Zn bridges. The glass density (rho) values increased from 3.490 to 3.573 g/cm(3), when the Yb content increased from 0.2 to 1.0 mol%. The optical transition values decreased from 3.076 eV to 2.936 eV as the Yb3+ ions increased from 0.2 to 1.0%. Judd-Ofelt theory is used to analyze the spectroscopic properties of the glass. The intensity parameter Omega(2) has higher values than Omega(4) and Omega(6) indicating to the covalent character of the glass. The calculated radiative lifetime tau(r) for the glass containing 1.0% Yb2O3 sample has the lowest value around 25 mu s. The absorption cross section sigma(a)(lambda) intensity increased from 1.632 x 10(-20) to similar to 1.9 x 10(-20) cm(-2) where the Yb content increased from 0.2 to 1.0 mol%, whereas the emission cross section sigma(e)(lambda) of the 0.8 Yb sample has the highest value at 1 x 10(-19) cm(-2).

Automated summary

A novel zinc borate glass doped with mixed rare-earth ions such as erbium and ytterbium was prepared by conventional melt annealing process. The study found that the glass density increased and the optical transition values decreased with increasing Yb3+ ion content. The Judd-Ofelt theory was used to analyze the spectroscopic properties of the glass, highlighting its high covalent character.