Novel Self‐Activated Zinc Gallogermanate Phosphor: The Origin of its Photoluminescence

Abstract

Since 2012, zinc gallogermanate has drawn interests as an excellent host phosphor for a variety of dopants (e.g., Cr3+, Bi3+ and Mn2+). However, the origin of its self‐activated luminescence has been largely unknown. Here, zinc gallogermanate of the composition Zn1+xGa2−2xGexO4 (0 ≤ x ≤ 1) is prepared by solid‐state reaction, and the evolution of the crystal structure with the composition is studied. The phosphors show a broad white‐bluish emission upon excitation by ultraviolet (UV) light, and the luminescence intensity greatly increases as Ga3+ are substituted by Ge4+. A full spectrum of the defects and trap centers responsible for the luminescence is given by a multiple characterization methods, such as low temperature electron spin resonance, positron annihilation lifetime and thermoluminescence spectra. The results show that the zinc gallogermanate is a promising self‐activated phosphor for a variety of applications.

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

“…The compositional evolution of the XRD patterns accord with Allix's work on the same materials as those studied in this work [9]. A more detailed study on the structure of zinc gallogermanate phosphors can also be referred to our recent publication [11].…”

“…It is found that Ga 2 O 3 and GeO 2 get evaporated slightly during the preparation course. Previous EPR study of the non-doped zinc gallogermanate indicates that the host matrix contains the gallium and germanium vacancies, which act as the emitting centers responsible for the self-luminescence of the nondoped phosphors [10,11]. XRD patterns of the samples are shown in Fig.…”

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

“…21 , it is very difficult to determine unambiguously the exact Zn 1+ x Ga 2−2 x Ge x O 4 phase in GCs, owing to the undistinguishable XRD patterns between the two end-members, ZnGa 2 O 4 ( x  = 0) and Zn 2 GeO 4 ( x  = 1). By comparing the Raman spectra of the crystallized glasses with the standard Zn 1+ x Ga 2−2 x Ge x O 4 polycrystals synthesized in our lab by solid-state reaction (for more detail, refer to our previous work 19 ), we provide the first direct evidence for the formation of Zn 1+ x Ga 2−2 x Ge x O 4 with x ≥ 0.4 in GCs (Fig. S1(b), supporting information).

Figure 1( a ) XRD patterns of the as-made Ni 2+ doped glass (ZGO-0.15PG), crystallized glass (ZGO-0.15GC) and standard ZnGa 2 O 4 crystal (PDF card no.

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Role of oxygen vacancies in long persistent phosphor Ca2Ga2GeO7: Zn2+

“…Hence, in this work, a simple fluorescence probe method was chosen, to prove the existence of with its effect on LPL performance. At present, germanates have been developed as LPL phosphors due to their low synthesis temperature, high stability, and reasonable conductivity as an oxide host . In this work, Ca 2 Ga 2 GeO 7 (CGG) with self‐activated properties was chosen as the host matrix.…”