Highly efficient energy transfer from Ge-related defects to Tb3+ ions in sol–gel-derived glasses

Abstract Luminescence and excitation spectra of sol–gel derived silica co-doped with Ge and Tb and treated in reducing atmosphere are reported. Energy transfer from Ge-related defects to Tb centers is demonstrated with an efficiency close to unity, resulting in all-inorganic sol–gel-derived materials with up to 30% quantum efficiency upon excitation under 254 nm radiation.