Preparation of Cerium‐Activated Silica Glasses: Phosphorus and Aluminum Codoping Effects on Absorption and Fluorescence Properties

Abstract

Cerium‐activated silica (SiO2) glasses were prepared by plasma torch chemical vapor deposition (CVD). In Ce‐doped SiO2 glasses, most Ce exists as Ce4+ ions; the remaining small amount of Ce3+ ions exhibits a broad fluorescence spectrum with a large Stokes shift, ∼9600 cm‐1, from the excitation spectrum peak of 324 nm. Aluminum and phosphorus codoping considerably increases the Ce3+ ratio and shifts the peaks of both spectra to shorter wavelengths. P codoping is the more effective way to achieve this result and in some cases produces an absorption spectrum similar to that of a Ce‐doped phosphate glass. These findings are consistent with the solvatiorn shell model for codoping, as previously proposed. To codope P, a soot remelting method was devised to deal with the highly volatile P2O5.