ACS Appl. Mater. Interfaces 2022, 14, 1, 1496–1504 https://pubs.acs.org/doi/10.1021/acsami.1c21321

Near-infrared (NIR)-persistent luminescence (PersL) materials are of promising applications in labeling, tracing, bio-imaging, and so forth, featuring distinctive self-sustained NIR light emitting. The PersL radiation spectrum, PersL duration, and charging efficiency are recognized as the key enablers for high-performance NIR PersL materials. Here, we have designed and developed a series of broad-band NIR superlong PersL phosphors (Sr,Ba) (Ga,In)₁₂O₁₉:Cr³⁺ with efficient UV-red light charging capacity. Typical SrGa_10.49In_1.5O₁₉:0.01Cr³⁺ presents intensive NIR PersL from 650 to 1000 nm peaking at ∼770 nm, with a PersL duration of 360 h. This material can be efficiently and repeatedly charged by solar radiation in various outdoor environments. Our work further identifies that this NIR PersL material is advantageous for labeling and tracing as a secret NIR additive and in situ bio-imaging as an optical probe under high tissue penetration red light excitation.

Mater. Today Chem. 2022,24 https://doi.org/10.1016/j.mtchem.2022.100806

Materials with the ability to persistently emit intense near-infrared (NIR) light after ceasing excitation are very useful in many fields. The persistent time is a vital parameter for successful applications. In this study, we developed an emerging NIR super-long persistent luminescent (PersL) material, Cr³⁺-activated magnetoplumbite oxide La(Zn/Mg)(Ga,Al)₁₁O₁₉:Cr³⁺, by doping Yb³⁺ as a new efficient electron trap and incorporating Al³⁺ to engineer the energy band. We show that fine control of the trap depth and density is the key underpinning for PersL enhancement. The title material emits intense PersL in the spectral range of 600–950 nm with a PersL time of more than 1,000 h. Furthermore, after undergoing such long-term decay, the NIR emission can be revived by photo-/thermo-stimulation. We demonstrate its potential uses in bioimaging, multilevel anti-counterfeiting, tracing, and positioning. This study provides insight into how energy band engineering manipulates electronic structures to achieve high-performance PersL. The new NIR persistent phosphor may be soon utilized in related applications.