Luminescence properties of Tm_2O_3-doped oxide glasses for NIR wideband light source

摘要

Abstract We have synthesized 0.5Tm2O3–45Sb2O3–10ZnO–(45−X)GeO2–XB2O3 (in nominal molar composition, X = 0, 5, 11.25, 22.5, 45) glasses as wideband near-infrared phosphors for LED-based light-sources. At the B2O3 composition of 5 mol%, luminescence intensity around 800 nm was higher than that around 1200 nm. On the other hand, beyond the B2O3 composition of 5 mol%, luminescence intensity around 800 nm was lower than that around 1200 nm. The maximum phonon energy increased with increasing the B2O3 composition. Changes in luminescence spectra indicated an enhancement of multi-phonon relaxations from 3H4 level to 3H5 level by substituting B2O3 for GeO2. Luminescence efficiency around 800 nm decreased with increasing the B2O3 composition. At the B2O3 composition of 11.25 mol%, luminescence efficiency around 1200 nm decreased with increasing the B2O3 composition. On the other hand, beyond the B2O3 composition of 11.25 mol%, luminescence efficiency around 1200 nm increased with increasing the B2O3 composition. These results indicated that the Tm2O3-doped borate glass is suitable for a practical NIR phosphor around 1200 nm.