Optical enhancement of nonstoichiometry-induced heterojunction in lanthanide doped double perovskite phosphors for WLEDs and scintillation applications

Nonstoichiometry-Induced Self-Activated Phosphors for Dynamic Anti-counterfeiting Applications

“…Here, it is speculated that the increased concentration of Zn 2+ in the Zn 2 GeO 4 phosphor can effectively increase the concentration of intrinsic defects, leading to an enhanced PL performance. The decay curves of the optimized Zn 2.2 GeO 4 phosphor by monitoring the wavelength at 446 and 535 nm are well-fitted by double exponential functions (Figure 2b) 26,27…”

“…Here, it is speculated that the increased concentration of Zn 2+ in the Zn 2 GeO 4 phosphor can effectively increase the concentration of intrinsic defects, leading to an enhanced PL performance. The decay curves of the optimized Zn 2.2 GeO 4 phosphor by monitoring the wavelength at 446 and 535 nm are well-fitted by double exponential functions (Figure b) , I ( t ) = A 1 nobreak0em.25em⁡ normalexp ( − t τ 1 ) + A 2 nobreak0em.25em⁡ normalexp ( − t τ 2 ) where I ( t ) refers to the luminescence intensity at time t , A 1 and A 2 are the corresponding fitted decay constants, and τ 1 and τ 2 denote the rapid and slow lifetimes, respectively. The fitting parameters R 2 both approached 1, and we also provided the decay parameters of the Zn 2.2 GeO 4 phosphor (Table S1 of the Supporting Information).…”

Crystal Field-Engineered Cr3+-Doped Gd3(MgxGa5–2xGex)O12 Phosphors for Near-Infrared LEDs and X-ray Imaging Applications

“…Therefore, the scintillator performances and potential applications of the synthesized GM 0.15 GG 0.15 :7.5% Cr 3+ phosphor are investigated. The absorption spectra of GM 0.15 GG 0.15 :7.5% Cr 3+ and commercial scintillators of Bi 4 Ge 3 O 12 (BGO) in the range of 1–100 keV are plotted in Figure S6. − The absorption coefficient of GM 0.15 GG 0.15 :7.5% Cr 3+ is higher than that of BGO in the range of 60–90 keV. Figure a displays the radiative luminescence (RL) spectrum of the GM 0.15 GG 0.15 :7.5% Cr 3+ sample under X-ray radiation (dose rate: 688.45 μGy s –1 , voltage: 15 kV), which is identical to the corresponding PL spectra.…”

Optical Signals for Quantitative and Qualitative Monitoring of Temperature‐Sensitive Products

“…The high‐energy component (peaks III and IV) is mainly assigned to the loosely bound oxygen, whereas the two low‐energy peaks (peaks I and II) are primarily assigned to the presence of oxygen vacancies. Since the variations of the oxygen vacancy concentration are related to the ratios of OII and OI intensities, [ 34–36 ] the corresponding ratio of the SYGO: 0.01Mn 2+ is larger than that of the SYGO sample. It suggests that the doping of Mn 2+ ions induces the generation of a significant number of oxygen vacancies, which may well act as the traps for capturing the carriers at low temperatures.…”