Extending the luminescence properties of zinc gallogermanate via co-doping with cost-effective metals ions (Cr3+/Mg2+, Cr3+/Ca2+, and Cr3+/Sr2+)

Abstract

The huge applications of red-light emitting materials paying the research attention to reduce the cost of production and raw materials. Therefore, abundant cations of alkaline earth metals e.g. Mg 2+ , Ca 2+ and Sr 2+ were successfully incorporated with Cr 3+ : Zn 3 Ga 2 Ge 2 O 10 (Cr-ZGGO) as co-activators via simple solidstate method. The X-ray diffraction (XRD) results of all samples con rmed the formation of zinc gallogermanate superstructure with two cubic phases ZnGa 2 O 4 and Zn 2 GeO 4 . The particle imaging of Cr-ZGGO and Ca@Cr-ZGGO via eld emission scanning electron microscopy (FE-SEM) reveals a signi cant change in morphology and particle size by Ca 2+ co-doping. Meanwhile, the energy dispersive X-ray spectroscopic analysis (EDS) and mapping techniques elucidate the exact chemical composition of the calculated stoichiometric substitution and illustrate the equal distribution of all elements over the whole sample. Optical band gap energy of Mg 2+ , Ca 2+ and Sr 2+ co-doped phosphors are lower than Cr-ZGGO.The Sr@Cr-ZGGO displays the most intense photoluminescence (PL) peak and the broadest emission in the near infra-red region (NIR) as a result of increasing light traps and generation of new paths between the energy levels of trapping centers.

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

“…Another route for tuning the PersL colour is co-doping other trap or activator ions, such as Cr 3+ /Mg 2+ , Cr 3+ /Ca 2+ , Cr 3+ /Sr 2+ , and Cr 3+ /Pr 3+ co-doping. 19,20 However, as far as we know, the Cr 3+ ,Mn 2+ co-doped ZGGO phosphor with dynamic colour changes has not been reported yet. 21 Herein, we synthesize multi-mode ZGGO:Cr,Mn afterglow phosphors by a hydrothermal method combined with high temperature annealing treatment.…”

Exploring the Synergistic Properties of ZnGa2O4:Cr3+ and Calcium Phosphate: Longer-Lasting Persistent Luminescent Nanocomposite Using Adenosine Triphosphate As a Phosphorus Source

“…Previous studies have introduced the possibility of manipulating the luminescence capabilities of PersL materials by incorporating different divalent cations that are suitable for ionic substitution. In a past study, Sanad reported an increase in luminescence intensity in Cr 3+ -doped Zn 3 Ga 2 Ge 2 O 10 when various alkaline earth metals (e.g., Mg 2+ , Ca 2+ , and Sr 2+ ) were added as dopants . The incorporation of these metal cations led to a decrease in bandgap and an overall increase in energy transfer paths, facilitating luminescence generation.…”

“…Due to the larger ionic radii of Ca 2+ relative to Zn 2+ , the successful substitution of Ca 2+ into the tetrahedral sites of CZGO would be indicated by a shift toward lower 2θ as highlighted in previous works. 53,54 However, the diffraction pattern of CZGO:Ca shows no noticeable shift. We also comparatively studied the luminescence intensity between CZGO@ACP-o, CZGO, and CZGO:Ca, which is shown in Figure S5.…”

“…In a past study, Sanad reported an increase in luminescence intensity in Cr 3+ -doped Zn 3 Ga 2 Ge 2 O 10 when various alkaline earth metals (e.g., Mg 2+ , Ca 2+ , and Sr 2+ ) were added as dopants. 53 The incorporation of these metal cations led to a decrease in bandgap and an overall increase in energy transfer paths, facilitating luminescence generation. In a separate study, Xu et al revealed that introducing Ca 2+ to solid-state synthesized Cr 3+ -doped Zn 3 Ga 2 Ge 2 O 10 can increase the luminescence of their PersL phosphor 15-fold, which they attributed to the formation of additional antisite defects by doping Ca 2+ into the tetrahedrally coordinated Zn 2+ site.…”