We report blue to green emission mechanoluminescence (ML) in CaZnOS:Bi3+,Li+ with about 50 times greater ML intensity than that of the strong ML material ZnS:Cu+.

Carbon dots (CDs) as new fluorescent materials with excellent fluorescence properties have shown enormous potential applications, especially in anticounterfeiting and cell imaging. Herein, nitrogen-doped CDs (NCDs) with excellent biocompatibility were prepared by a simple thermal sintering method. An extremely large red shift (∼130 nm) of the emission peak was observed when the excitation wavelength changes from 355 to 550 nm, indicating that NCDs are excellent fluorescent labeling materials for multiple cell imaging. On the other hand, NCDs showed obvious changes of emission intensity and peak position when the temperature increased from 223 to 323 K and the pH values changed from 1 to 13, respectively, which has been demonstrated by the “horse” pattern printed with NCD water-soluble fluorescent inks. The nontoxic NCDs dispersed in a multiple matrix are highly sensitive to excitation wavelength, temperature, and pH, indicating their great potential application in multiple anticounterfeiting and multiple cell imaging.

Mechanoluminescence (ML) is a classical optical phenomenon that is induced by mechanical stimulus, and it can be applied to stress sensors, imaging, self‐powered display/lighting and anti‐counterfeiting. However, the realization of determining the magnitude of stress in real time by the changes of colors for stress‐induced display/lighting has been fundamentally challenging. Herein, the superior manipulation of colors from blue to red continuously by pressure or concentration is achieved in Bi,Mn co‐activated CaZnOS for the first time. CaZnOS:Bi3+,0.1% Mn2+ exhibits the ML color from red, orange, white, and cyan with the pressure from 0 to 5000 N. Moreover, ML color manipulation from cyan to red light is also achieved with difference in Mn2+ concentration. It is of note that there is a reversible phase transition of CaZnOS according to in situ X‐ray diffraction and Raman spectra at high pressure. Moreover, the correlation between crystal structure and ML properties, as well as the ML mechanism are established and discussed in detail. In conclusion, the present results demonstrate the Bi,Mn co‐activated CaZnOS as a novel ML material achieving multi‐color manipulation with great potential applications in the fields of novel mechanically stress‐induced display, ultrasound monitoring, and particularly advanced anti‐counterfeiting technology.

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Much attention has been paid to exploit novel mechanoluminescnece (ML) phosphors, however, there is few reports about how to improve contrast in imaging and applicability in practice. In this work,...