Sunlight-activated long persistent luminescence in the ultraviolet-B spectral region from Bi³⁺-doped garnet phosphors for covert optical tagging

Abstract

Ultraviolet (UV) luminescent materials hold great promise for applications across a wide number of fields, whether environmental, biological or medical. However, luminescent materials with the capability to continue emitting UV...

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

“…All the spectra exhibit the same spectral profiles (shape and peak position) with the photoluminescence emission spectrum, indicating that the afterglow emission can be attributed to the electron transition of Bi 3+ emitters. 44 The UVA afterglow of Sr 3 Sc 2 Ge 3 O 12 :Bi 3+ sample can also be verified by using a UV camera in a bright indoor environment (Fig. 3c).…”

“…In recent years, Bi 3+ doped persistent phosphors that exhibit UV afterglow emission have attracted enormous attention. In the development of Bi 3+ -doped UV emissive persistent phosphors, silicates, germanates and garnets, such as CdSiO 3 , 36 ALnGeO 4 (A = Na, Li; Ln = Lu, Y and Sc), [37][38][39][40][41] and Y 3 (Ga,Al) 5 O 12 , [42][43][44] have been studied as host materials because of their good accommodation of Bi 3+ and suitable crystal-field strength for Bi 3+ emitters to achieve intense and tunable UV emissions. Among them, Y 3 (Ga,Al) 5 O 12 :Bi 3+ phosphors were found to emit intense ultraviolet-B (UVB; 280-320 nm) afterglow with the peak maximum shorter than 320 nm.…”

“…Among them, Y 3 (Ga,Al) 5 O 12 :Bi 3+ phosphors were found to emit intense ultraviolet-B (UVB; 280-320 nm) afterglow with the peak maximum shorter than 320 nm. [42][43][44] Meanwhile, Bi 3+ doped silicates and germanates (e.g., CdSiO 3 :Bi 3+ , 36 Sr 3 Y 2 Ge 3 O 12 :Bi 3+ 34 or ALnGeO 4 :Bi 3+ 37-41 ) can emit ultraviolet-A (UVA; 320-400 nm) persistent luminescence with the emission wavelength longer than 350 nm, which have also aroused significant interest in recent years considering their potential applications in energysaving catalysis and photomedicine. [45][46][47] However, to date, Bi 3+doped UV persistent phosphors with emission wavelengths over 320-350 nm have been relatively unexplored, even though tunable UV emission of Bi 3+ can be finely controlled by adjusting the crystal-field environment of the host materials.…”

Sunlight activated ultra-stable long persistent luminescence glass ceramic for outdoor information display

“…These electrons are slowly transferred to the neighboring Eu 2+ via tunneling process (processes 4-6) [36]. Under the visible light excitation, the Eu 2+ can be excited to an intermediate state with the assistance of phonon energy (process 7) and then its 5d state was populated by the input photons [37,38] In this case, the neighboring traps will be populated (process 8) followed by the PeL emission [37][38][39].…”

A multi-color persistent luminescent phosphor β-NaYF4:RE3+ (RE = Sm, Tb, Dy, Pr) for dynamic anti-counterfeiting

“…The release time of aerglow varies from several seconds to even several days depending on the luminescence matrix and additive. 10,11 A great number of novel persistent phosphors, such as SrAl 2 O 4 :Eu 2+ /Dy 3+ , ZnGa 2 O 4 :Cr 3+ and CaS:Eu 3+ /Ce 3+ , have been fabricated and used in targeted tumor PL imaging, multi-model imaging, bio-sensing, and even new energy source exploration. [12][13][14][15] However, due to the intrinsic shortcomings of solid-state method, these materials are generally coarse particles with obvious aggregation appearance, leading to the lowered luminous efficiency and limited development prospects.…”