Li-doping effects on the native defects and luminescence of Zn2GeO4 microstructures: Negative thermal quenching

Trap engineering through chemical doping for ultralong X-ray persistent luminescence and anti-thermal quenching in Zn2GeO4

“…The bluish-white emission of undoped Zn 2 GeO 4 under UV excitation has been attributed to DAP recombination. 21,22,24,34,35 In our previous work, 23 the blue-white and green emissions were ascribed to DAP transitions from V O and Zn i defects introduced in Zn-Zn and Zn-Ge rings, which was supported by DFT calculations. The broad PL in undoped Zn 2 GeO 4 indicated the complex nature of radiative transitions from different native defects.…”

“…[17][18][19] It is one of the defect-rich phosphors with oxygen vacancies (V O ), zinc interstitials (Zn i ), Zn and Ge vacancies (V Ge , V Zn ) and antisite defects (Zn Ge or Ge Zn ). [21][22][23] The whitebluish or green emission under UV excitation is originated from the donor (V O and Zn i )-acceptor (V Ge and V Zn ) pair (DAP) recombination. 22 Due to diverse applications of Zn 2 GeO 4 , a comprehensive investigation is a prerequisite to correlate the PL and afterglow with the electronic states and intermediate trap levels in Zn 2 GeO 4 .…”

“…[21][22][23] The whitebluish or green emission under UV excitation is originated from the donor (V O and Zn i )-acceptor (V Ge and V Zn ) pair (DAP) recombination. 22 Due to diverse applications of Zn 2 GeO 4 , a comprehensive investigation is a prerequisite to correlate the PL and afterglow with the electronic states and intermediate trap levels in Zn 2 GeO 4 . Several reports exhibited the visible emission of Zn 2 GeO 4 and investigated the spectral changes on doping of Mn 2+ , Bi 3+ , Yb 3+ and Li + ions.…”

“…Several reports exhibited the visible emission of Zn 2 GeO 4 and investigated the spectral changes on doping of Mn 2+ , Bi 3+ , Yb 3+ and Li + ions. 5,[22][23][24] In our previous work, a detailed experimental and theoretical investigation of PL due to defect states was carried out to realize the PersL bluegreen emission of Zn 2 GeO 4 . 23 Recently, Yuan et al 15 have also carried out an in-depth study of negative thermal expansion (NTE) mechanism of Zn 2 GeO 4 below room temperature (RT).…”

“…The NTE will result in increased stiffness of the Zn 2 GeO 4 lattice and can significantly suppress the emission loss due to thermal effects. 25,26 Dolado et al 22 investigated the electronic structure changes, optical output, and NTQ of Li-doped Zn 2 GeO 4 . Some other prominent works explored the bright green PersL in Mn 2+ -doped Zn 2 GeO 4 phosphors for applications in fluorescence latent fingerprinting, biosensing, and rewritable information storage.…”