Long-lifetime phosphorescence in diamond for data storage

The emergence of phosphorescence in diamonds has aroused great interest in their photoelectric information applications. Nevertheless, the existing phosphorescence in diamonds have a short lifetime, which severely restrains their application prospects. Moreover, the phosphorescence mechanism in diamonds is incomplete, which needs to be explored further. Herein, the synthetic diamonds with ultralong phosphorescence lifetime have been investigated. The phosphorescence emission bands centered at 470 nm and 580 nm have a long lifetime of 31 s and 93 s, respectively, outperforming other reported diamond materials. Detailed spectroscopy characterizations and density functional theory calculations reveal that the phosphorescence with ultralong lifetime involves a three-level system including donor, acceptor, and electron trap energy levels. The excited electrons can be captured by electron trap levels and transferred to the donor centers under thermal activation, then radiatively recombine with the holes from the acceptor level for persistent light emission. Based on the phosphorescence emission and photophysicochemical stability of the diamonds, a diamond-based data storage device has been demonstrated with outstanding repeatability (200 times with no attenuation) and durability (more than 3600 s). These results may prospect the application of phosphorescent diamonds in optical data storage.