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Self‐recoverable mechanoluminescence (ML) is becoming a novel technology widely used in the fields of sensing, display, and artificial intelligence. The dominant ML material, ZnS: Mn2+, is reported to solely present a yellow emission color, which limits the applications of self‐recoverable ML materials to a large extent. Herein, an effective strategy to extend the ML emission range of ZnS: Mn2+ by the ferromagnetic coupling of Mn2+ ions are reported. Under the thermal carbon‐reduction atmosphere (TCRA), the emission ranges of ML, photoluminescence (PL), and persistent luminescence spectra of ZnS: Mn2+ phosphors are all successfully broadened from yellow to red. Furthermore, as for the PL and ML intensities of ZnS: Mn2+, they are intensified to 1.76 and 3.23 folds larger under the TCRA treatment than those in pure nitrogen, respectively. Various spectra and magnetic test results reveal that the red emission bands of ZnS: Mn2+ @TCRA phosphors originate from the ferromagnetic coupling of Mn2+ ions. This study is the first to realize strong red emission and tunable multicolor luminescence in the conventional ZnS‐based phosphors, which introduces opportunities for discovering the multiband emissions of Mn2+ ion in other compounds. Brightly multicolored ZnS: xMn2+ @TCRA elastic films have been fabricated to demonstrate their anti‐counterfeiting and security applications. [ABSTRACT FROM AUTHOR]

Mechanoluminescence is a smart light‐emitting phenomenon in which applied mechanical energy is directly converted into photon emissions. In particular, mechanoluminescent materials have shown considerable potential for applications in the fields of energy and sensing. This study thoroughly investigates the mechanoluminescence and long afterglow properties of singly doped and codoped Sr2MgSi2O7(SMSO) with varying concentrations of Eu2+ and Dy3+ ions. Subsequently, a comprehensive analysis of its multimode luminescence properties, including photoluminescence, mechanoluminescence, long afterglow, and X‐ray‐induced luminescence, is conducted. In addition, the density of states mapping is acquired through first‐principles calculations, confirming that the enhanced mechanoluminescence properties of SMSO primarily stem from the deep trap introduced by Dy3+. In contrast to traditional mixing with Polydimethylsiloxane, in this study, the powders are incorporated into optically transparent wood to produce a multiresponse with mechanoluminescence, long afterglow, and X‐ray‐excited luminescence. This structure is achieved by pretreating natural wood, eliminating lignin, and subsequently modifying the wood to overall modification using various smart phosphors and epoxy resin composites. After natural drying, a multifunctional composite wood structure with diverse luminescence properties is obtained. Owing to its environmental friendliness, sustainability, self‐power, and cost‐effectiveness, this smart mechanoluminescence wood is anticipated to find extensive applications in construction materials and energy‐efficient displays. [ABSTRACT FROM AUTHOR]

Owing to their unique characteristic of direct mechanical‐to‐optical energy conversion, mechanoluminescence (ML) crystals have drawn considerable interest for visible stress sensing, flexible and stretchable displays, and advanced anti‐counterfeiting. However, among the visible emissions of synthetic ML materials, high‐performance red‐emission semiconductors with ideal color‐rendering indices are relatively scarce, which restricts their future applications. In this work, red ML emission with CIE coordinates (0.6395 and 0.3572) in Mn‐doped ZnGa2S4 prepared by a molten salt shielding synthesis method in the air is reported. ZnGa2S4 has a cubic crystal structure composed of a layered [ZnS4] tetrahedral unit that plays an important role in efficient ML. Based on density functional theory calculations, the relationship between ML performance and crystal structure is revealed, which will help in the development of new high‐quality ML materials. The Mn‐doping of ZnGa2S4 causes a slight deformation of the crystal structure, leading to band bending and the formation of ML features in response to mechanical stimuli. The deep‐red ML emission of the ZnGa2S4:Mn crystals prepared by this method holds great promise for advanced flexible and stable displays and force/pressure sensor applications. [ABSTRACT FROM AUTHOR]

Mechanoluminescence, a smart luminescence phenomenon in which light energy is directly produced by a mechanical force, has recently received significant attention because of its important applications in fields such as visible strain sensing and structural health monitoring. Up to present, hundreds of inorganic and organic mechanoluminescent smart materials have been discovered and studied. Among them, strontium‐aluminate‐based materials are an important class of inorganic mechanoluminescent materials for fundamental research and practical applications attributed to their extremely low force/pressure threshold of mechanoluminescence, efficient photoluminescence, persistent afterglow, and a relatively low synthesis cost. This paper presents a systematic and comprehensive review of strontium‐aluminate‐based luminescent materials' mechanoluminescence phenomena, mechanisms, material synthesis techniques, and related applications. Besides of summarizing the early and the latest research on this material system, an outlook is provided on its environmental, energy issue and future applications in smart wearable devices, advanced energy‐saving lighting and displays. [ABSTRACT FROM AUTHOR]

Mechanoluminescence (ML), as an optical response to deformation stimuli, shows great potential in high‐end stress sensing, ultrasonic field visualization, and multidimensional anti‐counterfeiting. However, processive practical applications in bio‐medicine are constrained by the discovery of near‐infrared (NIR) ML materials. Unlike lanthanides (Ln3+) with sharp multiplets, two kinds of Cr3+‐doped NIR ML materials, gallate spinel (ZnGa2O4:Cr3+, Zn3Ga2GeO8:Cr3+) and gallate magnetoplumbite (SrGa12O19:Cr3+) are here reported. Owing to the intrinsic cation antisite defects and cation vacancies in the matrix, these materials exhibit bright NIR ML under a relatively low load (20 N). In particular for SrGa12O19:Cr3+ (750 nm, peak; 100 nm, FWHM) with low persistent luminescence (PersL) interference, the ML behavior can be further rejuvenated under UV and sunlight irradiation. SrGa12O19:Cr3+ also shows bright NIR emission under photo‐ and thermo‐stimulation. Owing to their excellent tissue penetration and concealment capability, NIR ML materials show great potential in the fields of bio‐medicine and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Mechanoluminescent (ML) materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy, such as light or electricity. This alluring characteristic makes ML materials potentially applicable in a wide range of areas, including dynamic imaging of force, advanced displays, information code, storage, and anti-counterfeiting encryption. However, current reproducible ML materials are restricted to sulfide- and oxide-based materials. In addition, most of the reported ML materials require pre-irradiation with ultraviolet (UV) lamps or other light sources, which seriously hinders their practical applications. Here, we report a novel ML material, MgF 2 :Mn 2+ , which emits bright red light under an external dynamic force without the need for pre-charging with UV light. The luminescence properties were systematically studied, and the piezophotonic application was demonstrated. More interestingly, unlike the well-known zinc sulfide ML complexes reported previously, a highly transparent ML film was successfully fabricated by incorporating MgF 2 :Mn 2+ into polydimethylsiloxane (PDMS) matrices. This film is expected to find applications in advanced flexible optoelectronics such as integrated piezophotonics, artificial skin, athletic analytics in sports science, among others., Competing Interests: Conflict of interest The authors declare that they have no conflict of interest., (Copyright © 2021. Published by Elsevier B.V.)