Modeling Polyhedron Distortion for Mechanoluminescence in Mixed-Anion Compounds RE₂O₂S:Ln³⁺

Abstract

Mechanoluminescent (ML) materials with the characteristics of photon emission under mechanical stimulation show broad application prospects in building structural health diagnosis, biomechanical engineering, and wearable devices. However, existing ML materials cannot fully meet the requirements of different stress sensing applications due to the limited understanding of the structure and mechano-to-photon conversion mechanism of ML materials. Herein, we report novel ML materials with excellent self-recoverable ML performance in the family of mixed-anion compounds RE 2 O 2 S:Ln 3+ (RE = Y, Lu, La, Gd). The ML intensity is linearly related to the applied force, and the ML wavelength is tunable over a broad range of 514−1550 nm. More importantly, we construct a polyhedron distortion model that describes the local symmetry breaking. This model well explains the origin of ML and piezoelectricity in the compounds with centrosymmetric crystal structures. The findings may deepen the understanding of the microstructure and the mechano-to-photon conversion mechanism in ML materials and are expected to provide important guidance for the development of high-performance ML materials.

Recyclable Time–Temperature Indicator Enabled by Light Storage in Particles

“…As shown in Figure 4b, the TTI labels are composed of KZnF 3 :Mn 2+ SMPs and silicone resin, which are fabricated using a typical thermal curing method. [ 30,58 ] The SEM images confirm that the SMPs are homogeneously dispersed in the silicone resin (Figure S12, Supporting Information). The TTI labels exhibit excellent flexibility and stretchability.…”

High charge carrier storage capacity and wide range X-rays to infrared photon sensing in LiLuGeO4:Bi3+,Ln3+ (Ln = Pr, Tb, or Dy) for anti-counterfeiting and information storage applications

“…[10][11][12] Because of this feature, storage phosphors have many promising applications in X-ray computed tomography (CT), 13 dosimeters for radiation detection, [14][15][16] information storage, 17,18 anti-counterfeiting, 19 and even exploring mechanoluminescence materials for smart compression force sensing. 12,[20][21][22] There is a request to develop new afterglow and storage phosphors for exploring new applications such as advanced anti-counterfeiting and information storage. 6,23 In a storage phosphor, there are electron and hole-trapping centers that can temporarily store the free charge carriers.…”

LiTaO3:Bi3+,Tb3+,Ga3+,Ge4+: A Smart Perovskite with High Charge Carrier Storage Capacity for X‐Ray Imaging, Stress Sensing, and Non‐Real‐Time Recording

“…There is an ongoing research to develop more intense and stable ML materials. During the past two decades, different inorganic compounds, like LiNbO 3 , [ 6 ] Li 1‐x Na x NbO 3 , [7] AZnOS (A = Ca, Sr, Ba), [ 8 ] (Ca 1‐x Sr x ) 8 Mg 3 Al 2 Si 7 O 28 , [ 9 ] LiGa 5 O 8 , [ 10 ] KZn(PO 3 ) 3 , [ 11 ] NaCa 2 GeO 4 F, [ 12 ] MgF 2 , [ 13 ] or RE 2 O 2 S:Ln 3+ (RE = Y, Lu, La, Gd) [ 14 ] were explored. Compared with traditional phosphors, the numbers of compounds that can show repeatable ML are still very limited.…”