Photoluminescence profiles and fast/slow annealing effects of Eu(III)/Tb(III)‐codoped silica phosphor materials

Abstract

A silica (SiO2) nanoparticle matrix was codoped with luminescent Eu(III) and Tb(III) ions using a modified Stöber method. The effects of fast and slow thermal annealing on photoluminescence profile imaging were examined. Slow annealing treatment suppressed more quenching sites than fast thermal annealing to further increase the photoluminescence signals. The photoluminescence signals observed between 450 and 720 nm were assigned to the (5)D(0) → (7)F(J) (J = 0,1,2,3,4) of Eu(III) and the (5)D(4) → (7)F(J) (J = 6,5,4,3) transitions of Tb(III). Photoluminescence was largely sensitized by indirect excitation and was much stronger than that generated by direct excitation. The Eu(III) and Tb(III) ions were doped at lower symmetry sites in the silica matrix.

Improving green emission of Tb3+ ions in BaO‐B2O3‐P2O5 glasses by means of Al3+ ions

“…More specifically, the emission spectrum of Tb 3 + (under UV excitation) gives two prominent series of bands due to 5 D 4 → 7 F j and 5 D 3 → 7 F j ( j = 0…6) transitions. In most oxide glasses, the emission spectrum consists of four main bands centered at 620 nm (red), 580 nm (yellow), 550 nm (green), originating from the 5 D 4 level, and another in the high‐energy region centered around 440 nm (blue), originating from the 5 D 3 level . The energy gap between the 5 D 3 and 5 D 4 levels is approximately equal to the energy difference within the ground state levels of 7 F j (i.e.…”