Charge Traps in Ce-Doped CaF<sub>2</sub>and BaF<sub>2</sub>

In this paper we report preliminary results of optical studies on Y3 Al5012 (YAG) crystals codoped with Ce and Mg. By using measurements of luminescence, absorption, and luminescence excitation spectra we demonstrate that although the basic features introduced to the YAG host by the Ce-doping remain intact, the Mg-codoping imposes some significant changes on other properties of the material. These changes are potentially important for laser and/or scintillator applications of YAG:Ce and are due, most likely, to modifications of defect populations in the material. We characterize them by using the techniques of thermoluminescence and excited state absorption under excimer laser pumping. These techniques, interestingly, yield results that seem inconsistent. While the thermoluminescence signal of the Mg-doped sample is strongly reduced, suggesting that trap concentrations in the presence of Mg are suppressed, the excited state absorption signal, which we also relate to the traps, is higher. We offer a tentative explanation of this contradiction between the two experiments that involves a massive transfer of electrons from the Mg-related defects to the excited state absorption centers caused by the excimer pump itself.

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“…A more detailed description of the fitting procedure is given in Ref. [14]. The results of the fit are shown by a solid line in Fig.…”

Section: Resultsmentioning

confidence: 99%

Excited State Absorption and Thermoluminescence in Ce and Mg Doped Yttrium Aluminum Garnet

et al. 1999

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“…In the temperature range from 10 to 310 K we can distinguish, moreover, at least five TL peaks at about 95, 110, 130, 165, and 215 K that can be assigned to some types of traps (electron and hole types) present inside the bandgap of our crystal. The TL glow curves were fitted, using the classic 1st order equation based on the Randall-Wilkins model [19] and the procedure described in detail by Drozdowski et al [20]. The trap parameters, i.e.…”

Section: +mentioning

confidence: 99%

Growth and Optical Properties of Li₂B₄O₇Single Crystals Pure and Doped with Yb, Co and Mn Ions for Nonlinear Applications

et al. 2005

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The paper reports on the growth conditions of Li2B4O7 single crystals in both pure and Yb, Co, Mn doped systems. The crystals were grown by the Czochralski method using an intentional concentration of the above--mentioned ions at a level of 0.5 mol.%. The pure and Mn-doped crystals were found to be highly transparent and clear. The crystals doped with Yb 2 O 3 had a lot of precipitations making them opaque. The Co-doped crystals were purple-blue in colour and highly transparent. The growth of Yb and Co doped Li 2 B 4 O 7 crystals was reported for the first time in this paper. Absorption was measured in the range of 200 to 3200 nm, moreover analysis of changes in the absorption spectrum of γ-irradiated pure and doped Li 2 B 4 O 7 crystals was performed. Some thermoluminescence properties were measured, e.g. energies and lifetimes of the traps of different charge carriers occurring in the crystals at low temperatures.

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“…The transfer of energy from Ce 3+ to Dy 3+ ions in the Na 3 (SO 4 )F lattice brings Ce 3+ to the ground state and Dy 3+ to the excited state. The emission in Dy 3+ comes via a non-radiative transition to the 4 F 9/2 level, followed by radiative transitions to 6 H 15/2 and 6 H 13/2 level, which is shown in Figure 3.…”

Section: Resultsmentioning

confidence: 99%

“…The transfer of energy from Ce 3+ to Dy 3+ ions in Na 3 (SO 4 )Cl lattice brings Ce 3+ to the ground state and Dy 3+ to the excited state. The emission in Dy 3+ comes via a non-radiative transition to the 4 F 9/2 level followed by radiative transitions to 6 Selecting 268 nm excitation wavelength, the emission spectra was recorded for these samples. In this emission spectrum, curve a shows the emission for Ce 5mole% and Mn 0.2mole% , whereas curve b shows the emission for Ce 5mole% and Mn 0.1mole% contents.…”

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confidence: 99%

Dy³⁺and Mn²⁺ emission in fluoride‐ and chloride‐based Na₃(SO₄)X (X = F or Cl) phosphors

Gedam¹,

Dhoble

Moharil

2012

Luminescence

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In the present study, Na3 (SO4)X (X = F or Cl) halosulphate phosphors have been synthesized by the solid-state diffusion method. The phase formation of the compounds Na3 (SO4)F and Na3 (SO4)Cl were confirmed by X-ray powder diffraction (XRD) measurement. Photoluminescence (PL) excitation spectrum measurement of Na3 (SO4)F:Ce3+ and Na3 (SO4)Cl:Ce3+ shows this phosphor can be efficiently excited by near-ultraviolet (UV) light and presents a dominant luminescence band centred at 341 nm for Ce3+, which is responsible for energy transfer to Dy3+ and Mn2+ ions. The efficient Ce3+ → Dy3+ energy transfer in Na3 (SO4)F and Na3 (SO4)Cl under UV wavelength was observed due to 4 F(9/2) to 6H(15/2) and 6H(13/2) level, while Ce3+ → Mn2+ was observed due to (4) T1 state to (6) A1 . The purpose of the present study is to develop and understanding the photoluminescence properties of Ce3+ -, Dy3+ - and Mn2+ -doped fluoride and chloride Na3 (SO4)X (X = F or Cl) luminescent material, which can be the efficient phosphors in many applications, such as scintillation applications, TL dosimetry and the lamp industry, etc.

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Charge Traps in Ce-Doped CaF₂and BaF₂

Cited by 18 publications

References 12 publications

Excited State Absorption and Thermoluminescence in Ce and Mg Doped Yttrium Aluminum Garnet

Excited State Absorption and Thermoluminescence in Ce and Mg Doped Yttrium Aluminum Garnet

Growth and Optical Properties of Li₂B₄O₇Single Crystals Pure and Doped with Yb, Co and Mn Ions for Nonlinear Applications

Dy³⁺and Mn²⁺ emission in fluoride‐ and chloride‐based Na₃(SO₄)X (X = F or Cl) phosphors

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Charge Traps in Ce-Doped CaF2and BaF2

Cited by 18 publications

References 12 publications

Excited State Absorption and Thermoluminescence in Ce and Mg Doped Yttrium Aluminum Garnet

Excited State Absorption and Thermoluminescence in Ce and Mg Doped Yttrium Aluminum Garnet

Growth and Optical Properties of Li2B4O7Single Crystals Pure and Doped with Yb, Co and Mn Ions for Nonlinear Applications

Dy3+and Mn2+ emission in fluoride‐ and chloride‐based Na3(SO4)X (X = F or Cl) phosphors

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Product

Resources

About

Charge Traps in Ce-Doped CaF₂and BaF₂

Growth and Optical Properties of Li₂B₄O₇Single Crystals Pure and Doped with Yb, Co and Mn Ions for Nonlinear Applications

Dy³⁺and Mn²⁺ emission in fluoride‐ and chloride‐based Na₃(SO₄)X (X = F or Cl) phosphors