Broadly tunable emission from Mn-doped zinc gallogermanate phosphors through composition modification

Abstract

Nowadays, one-phase and full-color phosphors have gained increasing interest. Here, we show that Mn-activated zinc gallogermanate, Zn 1+x Ga 2-2x Ge x O 4 : Mn, x = 0 ~1, phosphors exhibit a broadly tunable luminescence from green to deep red with the substitution of Ga 3+ by Ge 4+ . The green and deep red emissions are attributed to Mn 2+ and Mn 4+ occupying the tetrahedrally coordinated Zn 2+ and octahedrally coordinated Ga 3+ sites, respectively. The origin of the tunable luminescence is discussed. The present phosphors have potential uses in field emission displays and in vivo bio-imaging. The in vivo activation of persistent nanophosphors for optical imaging of vascularization, tumours and grafted cells," Nat.

Selective doping of Ni2+ in highly transparent glass-ceramics containing nano-spinels ZnGa2O4 and Zn1+x Ga2−2x Ge x O4 for broadband near-infrared fiber amplifiers

“…Pure Zn 1+ x Ga 2−2 x Ge x O 4 spinels can be synthesized for x ranging from 0 to 0.5 19 . Our recent study of Mn doped Zn 1+ x Ga 2−2 x Ge x O 4 phosphors shows that the substitution of Ge 4+ for octahedrally coordinated 6 Ga 3+ helps to separate Mn 4+ which also substitutes for 6 Ga 3+ , thus resulting in an enhanced emission of Mn 4+ 38 . It is assumed that a similar separating effect exists for Ni 2+ as well, i.e., 6 Ni 2+ ions are well separated in the ZGGO GCs, and thus the concentration quenching is postponed.…”

Regulation of red to near-infrared emission in Mn2+ single doped magnesium zinc phosphate solid-solution phosphors by modification of the crystal field

“…The decay time of Mn(I) with red emission is measured to be 40-47 ms, while Mn(II) has a shorter lifetime of approximately 6-8 ms. 24 Furthermore, the results show that the emissions of Mn(I) and Mn(II) originate from different lattice sites of Mn ions, corresponding to the inference mentioned above. An overlap between the PLE spectrum of Mn(II) and the PL spectrum of Mn(I) in the range of 550-600 nm is observed, which suggests an occurrence probability of energy transfer from Mn(I) to Mn(II).…”

Regulating Mn2+/Mn4+ Activators in ZnGa2O4 via Mg2+/Ge4+ Doping to Generate Multimode Luminescence for Advanced Anti-Counterfeiting

“…This phenomenon was also reported by Xu et al in Zn 1+x Ga 2−2x Ge x O 4 :Mn phosphor. 57 Monitored at 668 nm, two broad bands were observed in the excitation spectra ranging from 250 to 550 nm in Figure 7a, which are different from that observed in Figure 6a (monitored at 505 nm). It can be seen from Figure 7b that the spectra can be fitted by the Gaussian function, with three maxima at ∼317 nm (excitation band I), ∼372 nm (excitation band II), and ∼465 nm (excitation band III).…”