Modulating trap properties by Cr3+-doping in Zn2SiO4: Mn2+ nano phosphor for optical information storage

Photo-stimulated luminescent materials are one of the most attractive alternatives for next-generation optical information storage technologies. However, there are still some challenges in regulating appropriate energy levels of traps in luminescent materials for optical information storage. Herein, a green emission nanophosphor Zn2SiO4: Mn2+, Cr3+ with the trap depth of 1.05 eV, fulfilling the requirements for optical information storage, was fabricated for the first time through the solution combustion method and subsequent heat treatment at 1000 °C for 2 h. The crystal structure, micromorphology, photoluminescence (PL), photoluminescence excitation (PLE), and afterglow properties of Zn2SiO4: Mn2+, Cr3+ were studied systematically. By applying the strategy of trap depth engineering, high trap density with proper trap depth was observed when Cr3+ ions were introduced into Zn2SiO4: Mn2+. Thermoluminescence (TL) glow-curve analysis through the initial rise (IR) method was conducted to gain some insights into the information of traps. As proof of application, optical information storage was experimentally achieved by choosing 275 nm illumination for "information writing" and 980 nm NIR excitation for "information reading". The results indicate that Zn2SiO4: Mn2+, Cr3+ phosphor holds promise for potential applications in the field of optical information storage.