Trap-Dependent Optical/Thermal Stimulated Luminescence of Gallate Phosphors Charged by UV-visible-NIR light for Multiplexed Data Storage

UV-charged optical stimulated single-band phosphors are being used for single-level optical data storage because of their ability to easily write/read information by light. In contrast, UV-visible-NIR rechargeable optical stimulated double-band phosphor is urgently necessary for multiplexed high-throughput optical data storage. Here, the authors design and synthesize Mn2+,Cr3+ co-doped zinc gallate storage persistent phosphor that exhibits strong red-green bicolor persistent luminescence (PersL). Besides the traditional ultraviolet charging, the phosphor can be effectively and repeatedly charged by using visible and NIR light by one- or two-photon process. Interestingly, red and green PersL exhibit the opposite temperature dependence, which is extremely important for multilevel information storage. The mechanism of temperature-dependent PersL intensity based on different trap types and filling approaches for the double luminescence centers is proposed. The phosphor promises a sophisticated application in optical data storage of wavelength multiplexing.