Colour evolution of dynamic persistent luminescence of Zn₃Ga₂Ge₂O₁₀:Cr³⁺,Mn²⁺ phosphors for advanced anti-counterfeiting

Abstract

The ZGGO:Cr,Mn phosphors exhibit color-changeable photoluminescence and persistent luminescence via excitation wavelength and temperature management, showing the enormous potential for anti-counterfeiting and information storage applications.

Achieving Multicolor Anti‐Counterfeiting via Simultaneous X‐Ray and UV/Blue Excitation in Ca2YMgScSi3O12: Mn2+

“…In addition, the significant extension of the deep-red emission lifetime provides evidence to rule out the Mn 2+ -Mn 2+ pair in CYMSS as the source of deep-red emission. [27][28][29][30] It is believed that Mn 2+ ions entering tetrahedral and octahedral lattice sites in CYMSS can form green and red emission centers, respectively, [36] the higher local symmetry of the [Ca/YO 8 ] dodecahedron will result in the longer wavelength emission of the weaker Mn 2+ ions, so the emission of 720 nm is attributed to the Mn 2+ ions occupying the dodecahedron, which is consistent with the paper reported by J.A. Hernández, E.G.…”

“…[25,26] Based on the empirical equation: E = T 500 , [22] where T is temperature and E is the trap depth, the trap depths were calculated to be 0.70 and 0.84 eV, respectively, which obviously certify that the self-PL stemmed from oxygen vacancy. [27] Figure 2c describes the luminescence intensity of CYMSS: xMn 2+ at 400, 590, and 720 nm under the 254 nm excitation as the function of Mn 2+ ions content, which gives the distinguished intensity changing trend. In addition, the luminescence of CYMSS: xMn 2+ under 365, 395, and 463 nm excitation also changed significantly, indicating that CYMSS: xMn 2+ have multidimensional luminescence characteristics, as shown in Figure 2d and Figure S5 (Supporting Information).…”

Simultaneous NIR photoluminescence and mechanoluminescence from Cr3+ activated MgGa2O4 phosphors with multifunctions for optical sensing

“…Recent reports indicate that the active ions contributing to near-infrared (NIR) emission are mainly transition metal ions (Mn 2+ , Cr 3+ , and Ni 2+ ), 13 Ln 3+ doped ions (Eu 3+ , Tb 3+ , Er 3+ , and Tm 3+ ), 14 and main group metal ions (Bi 3+ and Bi 2+ ). 15–17 Near-infrared phosphors can be categorized into three groups based on their activating ions: those activated by rare earth ions, main group ions, and transition metal ions. 18 Cr 3+ is extensively investigated as an activator of near-infrared luminescence, serving as a representative transition metal ion with partially filled d orbitals.…”

Stimulated-source-independent persistent luminescence phosphor Sr2Ta2O7:Tb3+, Tm3+ for multi-mode anti-counterfeiting applications

“…4,5 However, traditional luminescence anti-counterfeiting materials generally emit single-mode down-conversion (DC) or up-conversion (UC) static photoluminescence (PL), 6,7 and are highly susceptible to being cracked and counterfeited. 8,9 In response to this, luminescent materials have been combined with a variety of stimulation modes using different methods, and multi-mode luminescent anti-counterfeiting materials came into being, which were usually easily copied mixture combinations or possessed a complicated core–shell structure. 10,11…”