Time‐Resolved Bright Red to Cyan Color Tunable Mechanoluminescence from CaZnOS: Bi³⁺, Mn²⁺ for Anti‐Counterfeiting Device and Stress Sensor

Abstract

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.

Multiple Color Emission of Mechanoluminescence and Photoluminescence from SrZnSO: Bi3+ for Multimode Anticounterfeiting

“…However, the strongest ML does not ( x = 0.01) appear in the materials with the deepest depth ( x = 0.001) or the highest trap concentration ( x = 0.04), which implies the complexity of carrier transport in the current ML system . Furthermore, the peak bands at about 80 °C and the trap depth of about 0.72 eV benefit from afterglow . ThL curves of Sr 0.999 Bi 0.001 ZnSO as a function of temperature are depicted in Figure d.…”

Enabling narrowband cyan photoluminescence and long-lasting ultraviolet-A persistent luminescence in Bi3+ single-doped Sr3Sc2Ge3O12 phosphors by selective site occupation

“…7–12 To date, Bi 3+ doped phosphor materials have aroused considerable attention because of their unique luminescence performances, which enable researchers to find important applications in a wide range of fields such as solid-state lighting, optical information storage, optical tagging and anti-counterfeiting. 13–16 For example, for phosphor-converted white LED applications, most Bi 3+ -doped phosphors usually show broad absorption bands in the UV region due to the transition from the 1 S 0 ground state to the 3 P 1 excited state and emit tunable colors in the visible spectral region. 17,18 The avoidance of spectral overlap between their excitation and emission bands can reduce the efficiency loss and greatly increase the luminous efficiency.…”

Ternary-Host and Heterojunction Enabled Eye-Visible Elastic Mechanoluminescence from (Ca0.5Sr0.5)ZnOS/xZnS/Mn2+

“…ML materials can be roughly divided into fracto-ML and elastic-ML materials . The elastic-ML materials are being strongly anticipated as a promising alternative to the fluorescent materials for stress sensing, , anticounterfeiting, , onsite infrastructure diagnosis, bioimaging, flexible optoelectronics, and biomimetic multifunctional E-skins , because elastic-ML materials tend to produce even brighter and more reproducible ML than fracto-ML materials . Up to now, a series of elastic ML materials have been proposed by doping transition metal ions (e.g., Mn 2+ , Cu 2+ ) or rare-earth ions (e.g., Eu 2+ , Pr 3+ , Sm 3+ , and Nd 3+ ) into piezoelectric host materials, such as ZnS/Mn 2+ , , ZnS/Cu 2+ , CaZnOS/Mn 2+ , , SrAl 2 O 4 /Eu 2+ , BaSi 2 O 2 N 2 /Eu 2+ , , Ca 2 Al 2 SiO 7 /Eu 3+ , LiNbO 3 /Pr 3+ , CaZr­(PO 4 ) 2 /Mn 2+ , and so on.…”