Colorless Bi₂O₃-containing borophosphate glasses with high refractivity

Abstract

The effects of P 2 O 5 substitution on the coordination structure of a Bi 3+ in Bi 2 O 3 -B 2 O 3 glasses were examined by applying 11 B and 31 P MAS-NMR spectroscopy. Observation of the wide optical bandgap after the substitution revealed a substantial difference in the solvation shell structure between the P 2 O 5 substituted and the P 2 O 5 -free Bi 2 O 3 -containing glasses, i.e., the P 2 O 5 substitution replaced by the B 2 O 3 is effective for forming the solvation shell, which leads to weak ligand field around a Bi 3+ . We report the optical properties of the Bi 2 O 3 -P 2 O 5 -B 2 O 3 glass providing a wide optical bandgap (³3.6 eV) and high refractive index (³2.0).