RESUMEN
We report a novel Nd3+ and Eu3+ co-doped Sr2SnO4 (SSONE) phosphor showing the capability of "write-in" and "read-out" in optical information storage. As-prepared phosphors exhibit a dominant emission (PL) band centered at 596â nm under UV excitation, closely identical with its photo-stimulated luminescence (PSL) spectrum center (595â nm) upon near-infrared (NIR) light and thermal-stimulated luminescence (TSL) spectrum center (595â nm) under heat source. Remarkably, compared with Eu3+ single-doped phosphors, the co-doping strategy enhances the deep traps and also separates the deep traps with shallow traps, which are very crucial factors for optical information storage in electron trapping materials. Further, a demonstration confirmed the optical information storage capacity by photo- and thermal-stimulating the prepared phosphors filled in the designed patterns.
RESUMEN
In recent years, the efficiency of combinatorial methods has been utilized to accelerate the finding or screening of inorganic materials. In this work, based on the double substitution strategy of the cation ions Me2+/Si4+, a series of Me y Y3-y Al5-y Si y O12:Eu x garnet phosphors (MeYASG:Eu, Me = Mg, Ca, Sr, Ba) were rapidly prepared and screened by a combinatorial method in microreactor arrays. Through parallel experiments of solid-state synthesis, the reliability of the combinatorial screening was verified and an optimal composition of CaY2Al4SiO12:Eu0.03 (CYASG:Eu) with advanced luminous intensity was obtained. Annealing experiments under air and reductive atmospheres were performed and demonstrated the controllability and reversibility of the Eu3+ â Eu2+ valence transition process, thus realizing the tuning of the dominant emission from divalent Eu2+ or trivalent Eu3+. The optimal CYASG:Eu sample showed excellent thermal quenching resistance after annealing at 800 °C for 1 h in a reducing atmosphere. The abnormal intensity of PL increased by 10% in the 50-100 °C region, and retained 63% of the initial value at 250 °C. With the assistance of thermoluminescence characterization, the complementary effect of the release of captured electrons or charge carriers in trap levels on the abnormal increase of PL intensity during the high-temperature luminescence process was revealed. By combination of the double substitution strategy of cations and annealing, a new approach is proposed to creating the coexistence of activator Eu ions with a mixed-valence state. Also, the prepared CYASG:Eu phosphors have promising applications in fields such as plant light supplements in greenhouses and plant factories and as luminescent materials for energy-saving light sources.