Red-shift and improved afterglow of Sr3Al2-xBxO5Cl2:Eu2+, Dy3+ phosphors via a cation substitution strategy

Narrow-Band Deep-Blue Emission and Superior Thermal Stability of Fluoroaluminate Phosphor Based on Tungsten Bronze-Type Mineral Structure

“…In addition, another two characteristic XPS peaks located at 1165.2 and 1137.6 eV and ascribed to the 3d3/2 and 3d5/2 orbits of the Eu 3+ ion are also observed in the high-resolution XPS spectrum, indicating the existence of trace amounts of Eu 3+ ion in our TB-type phosphor [39]. Such a mixed valence state of Eu in crystalline solids is mainly attributed to the interaction between the incomplete reduction of Eu 3+ in the relatively weak reducing atmosphere of CO and the effect of surface oxidation [40]. Nevertheless, as exhibited in Figure 4b, the PL spectrum of our representative phosphor exhibits only It can be found that the photoelectron peaks of Al 2p, 2s, C 1s, K 2p, Ca 2p, K 2s, O 1s, and F 1s and auger peaks of F, O, and K appear at 74.8, 120.0, 284.2, 293.2, 347.9, 377.0, 531.1, 685.0, 833.0, 977.0, and 1238.0 eV, corresponding with the theoretical values of 72.9, 117.9, 285.0, 295.0, 346.6, 377.2, 531.8, 685.7, 833.0, 979.7, and 1235.0 eV, respectively [37].…”

“…In addition, another two characteristic XPS peaks located at 1165.2 and 1137.6 eV and ascribed to the 3d 3/2 and 3d 5/2 orbits of the Eu 3+ ion are also observed in the high-resolution XPS spectrum, indicating the existence of trace amounts of Eu 3+ ion in our TB-type phosphor [ 39 ]. Such a mixed valence state of Eu in crystalline solids is mainly attributed to the interaction between the incomplete reduction of Eu 3+ in the relatively weak reducing atmosphere of CO and the effect of surface oxidation [ 40 ]. Nevertheless, as exhibited in Figure 4 b, the PL spectrum of our representative phosphor exhibits only one narrow emission band peaking at 400 nm owing to the characteristic 4f 6 5d 1 –4f 7 transition of the Eu 2+ ion, while no typical narrow 5 D 0 – 7 F J (J = 1, 2) transition lines of the Eu 3+ ion are observed in the region of 590–620 nm.…”

Host–Guest Metal–Organic Frameworks-Based Long-Afterglow Luminescence Materials

“…For inorganic afterglow materials, the long decay time of persistent luminescence is generally believed to be due to the fact that the excitation energy is stored in the trap and gradually released from the trap with the help of thermal energy [5]. Inorganic long-afterglow materials are composed of either transition metals compounds [6] or rare-earth metal compounds [7], mainly including rare-earth-doped aluminate [8,9], silicate [10][11][12], stannite [13], phosphate [14,15], gallate [16,17] and germanate [18,19], which usually require high-temperature calcination to obtain. Organic materials with long afterglows include carbon-based materials [20,21], organic dyes [22,23], polymer-based materials, [24][25][26][27], etc.…”