White‐light emission and red scintillation from Mn2+ ions single‐doped aluminum‐silicate glasses

Abstract A series of Mn 2+ single‐doped 0.2Gd 2 O 3 ‐0.2Al 2 O 3 ‐0.6SiO 2 (GAS: xMn 2+ ) glasses with Si 3 N 4 as reducing agent were prepared. The presence of [SiO 4‐x ] defects and Mn 2+ ions was determined from the absorption and excitation spectra of the glasses. With the increase of Mn 2+ concentration, the intensity of blue emission decreases, while the intensity of red emission increases. The color coordinate of GAS: 6Mn 2+ glass is (0.264, 0.226). The lifetime of the glasses was tested. Under the monitoring of 440 nm, the fast components (τ f ) are between 17 and 85 μs, and the slow components (τ s ) are between 200–650 μs. The former belongs to [SiO 4‐x ] defects, and the latter is [ 4 E(G), 4 A 1 (G)]→ 6 A 1 (S) transition of Mn 2+ ions. Under the monitoring at 630 nm, the τ f are between 110 and 300 μs, and the τ s are between 680 and 1220 μs, which are due to 4 T 1 (G)→ 6 A 1 (S) transition of Mn 2+ ions and Mn 2+ pairs, respectively. The energy transfer mechanism of [SiO 4‐x ] defect→Mn 2+ ions are explained. The efficient [SiO 4‐x ] defect →Mn 2+ ions energy transfer process was demonstrated by time‐resolved photoluminescence, and the energy transfer efficiency is over 85%. The maximum photoluminescence quantum yield (PL QY) of the glasses can reach 15.87%. The thermal activation energy of the glasses was calculated. In addition, X‐ray excited red luminescence spectra and the mechanism of the glasses were investigated.