Self‐Recoverable Mechanically Induced Instant Luminescence from Cr³⁺‐Doped LiGa₅O₈

Abstract

Currently, most of the mechanoluminescence (ML) phosphors strongly depend on postirradiation stimulation using ultraviolet light (denoted as “UV exposure” from hereon) to show the ML. However, only a few transition metal cations are proven to be effective luminescence centers, which hinder the development of more ML phosphors. This study reports a self‐recoverable deep‐red‐to‐near‐infrared ML using Cr3+‐doped LiGa5O8 phosphor with fully recoverable ML performance. The ML performance can be further optimized by tuning the trap redistributions by codoping the phosphor with Al3+ and Cr3+ cations. Theoretical calculations reveal the important role of Cr dopants in the modulation of local electronic environments for achieving the ML. Owing to the induced interelectronic levels and shallow electron trap distributions, the electron recombination efficiency is enhanced both through direct tunneling and energy transfer toward the dopant levels. Moreover, the ML of Cr3+‐doped LiGa5O8 can penetrate a 2‐mm‐thick pork slice, showing that it can have wide‐ranging in vivo applications, including the optical imaging of intracorporal stress/strain distribution and dynamics. Therefore, this work fabricates a novel ML material with self‐recoverable luminescence in an extended wavelength range, increasing the number of potential ML candidates and promoting the fundamental understanding and practical applications of ML materials.

Cubic Spinel XIn2S4 (X = Fe, Co, Mn): A New Type of Anode Material for Superfast and Ultrastable Na‐Ion Storage

“…03-065-7271; Figure 1f). The refinement results show the reasonable fit with the low Chi 2 values around 2, [28] confirming the pure In-based cubic spinel structure of the as-prepared samples without other impurities. Their unit cell volumes from the refinement results are around 1200 Å 3 (Table S1, Supporting Information), and the large unit cell volumes are beneficial for Na-ion diffusion and storage applications.…”

Defect Enrichment in Near Inverse Spinel Configuration to Enhance the Persistent Luminescence of Fe3+

“…The suitable trap depth is situated at 0.6-0.9 eV for the excellent PersL performance, the slightly higher trap depth of MGO:Fe 3+ manifests that the captured carriers in this material system are not easy to release at RT. [53] In addition, the trap depth versus T exc plot can be well fitted by one linear equation function, suggesting that the de-trapping rate is constant above RT, and it is considered as one "type" trap due to the presence of uniform and continuous trap distribution. [54] We consider that the carriers released in the PersL process are neutral excitons or the pair of electrons and holes instead of single electrons or holes, which is consistent with previous discussion.…”

Recent Advances in Mechanoluminescence of Doped Zinc Sulfides

“…Also, near-infrared (NIR) ML spectrum can be effectively used in vivo bioimaging which can easily penetrate through body tissues compared with the traditional bioimaging devices and for stress sensors. [6][7][8][9][10] However, the development of such EML with corresponding characterizations is still a big challenge for researchers. [11] 20 years ago, Xu et al developed an intense and recoverable ML material of a manganese-doped ZnS (ZnS:Mn).…”