Preparation and luminescence properties of Eu2+ -doped CASN-sinoite multiphase system for LED

We have investigated the local luminescence properties of Eu-doped CaAlSiN3 by using low-energy electron beam (e-beam) techniques. The particles yield broad emission centered at 655 nm with a shoulder at higher wavelength under light excitation, and a broad band around 643 nm with a tail at 540 nm under e-beam excitation. Using cathodoluminescence (CL) in a scanning electron microscope (SEM), we have observed small and large particles, which, although with different compositions, exhibit Eu2+-related emissions at 645 and 635 nm, respectively. Local CL measurements reveal that the Eu2+ emission may actually consist of several bands. In addition to the red broad band, regularly spaced sharp peaks have been occasionally observed. These luminescence variations may originate from a variation in the composition inside CaAlSiN3.

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“…All the peaks can be attributed to CASN (JCPDS No. 39-0747) [38, 40, 54]. These peaks are sharp and intense, indicating good crystallinity.…”

Section: Resultsmentioning

confidence: 99%

“…They may originate from an inhomogeneous distribution of Si/Al, a partial replacement of N ions by O impurities for the same crystallographic site and/or the occupation of Eu into different sites in CASN [54, 65–69]. Such changes will induce a change in the covalency, and therefore in the Stokes shift.…”

Section: Resultsmentioning

confidence: 99%

Local analysis of Eu²⁺emission in CaAlSiN₃

Dierre

Takeda

Sekiguchi

et al. 2013

Science and Technology of Advanced Materials

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“…Obviously, all diffraction peaks of the PiGs are almost consistent with those of the corresponding MPs, implying that the doped MPs can survive in the glass matrix without producing any impurity and their structures keep unchanged during the sintered process. However, compared to the standard JCPDS data, some diffraction peaks of CAS-PiG are shift and split, possible due to the form of some impurity AlN and Si 2 N 2 O during the preparation of the commercial CAS MPs [20]. As shown in figure 2(b), a typical SEM image of the SAO and CAS co-doped PiG (denoted as SC-PiG) demonstrates the distribution of some MPs among the glass matrix, which may be SAO and CAS MPs.…”

Section: Resultsmentioning

confidence: 96%

“…Figures 6(d) and (e) exhibit the schematic mechanisms for PL of Eu 2+ in SrAl 2 O 4 [20,21] and PersL of Eu 2+ in CaAlSiN 3 [22,23], respectively. When CAS-PiG excited at 365 nm, electrons are promoted from the ground state (4f 7 ) to the excited state (4f 6 5d 1 ) (process 1), and then most of the excited electrons return to the ground state and generate red PL (process 2).…”

Section: Resultsmentioning

confidence: 99%

Phosphor-in-glass with time-evolving multicolor luminescence for dynamic anticounterfeiting

Zhu

Yu²,

Li³

et al. 2023

Mater. Res. Express

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The conventional luminescence materials used in the anticounterfeiting field generally exhibit unicolor output and a single-wavelength excitation mode, resulting in a poor anticounterfeiting effect. Herein, we successfully achieved a new transparent SrAl2O4:Eu2+,Dy3+/CaAlSiN3:Eu2+ phosphor-in-glass (PiG) with dynamic luminescence color variation from red to yellow in hundreds of seconds during the ultraviolet lamp irradiation and green persistent luminescence (PersL) after ceasing excitation. Additionally, the prepared PiG owns excitation wavelength- or doping weight ratio-dependent color-tunable luminescence. As a proof-of-concept experiment, the specially designed SrAl2O4:Eu2+,Dy3+/CaAlSiN3:Eu2+ PiG based flower patterns exhibit dynamic luminescence color variation under a simple ultraviolet lamp, and can be observed for quick discrimination. This work exploits a new perspective for the design of dynamic multicolor anticounterfeiting materials.

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“…[13][14][15] At present, phosphors with a wavelength of 660 nm have been extensively studied. [16][17][18][19][20] Therefore, the blue-green phosphor in the 490nm band is a key issue in the research and preparation of full-spectrum LEDs. Currently, some blue-green phosphors, for example silicate (M 2 SiO 4 : Eu 2+ , M = Ca, Ba, Sr), sulfide (M 2 BS 4 : Eu 2+ , M = Ba, Sr, Ca, B = Al, Ga, In) aluminate (MSrAl 37 : Eu 2+ , M = Y, La, Gd), have been developed.…”

Section: Introductionmentioning

confidence: 99%

Effect of sintering temperature on luminescence properties of borosilicate matrix blue–green emitting color conversion glass ceramics*

Zheng¹,

Yang²,

Wu³

et al. 2019

Chinese Phys. B

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The color conversion glass ceramics which were made of borosilicate matrix co-doped (SrBaSm)Si2O2N2: (Eu3+Ce3+) blue–green phosphors were prepared by two-step method in co-sintering. The change in luminescence properties and the drift of chromaticity coordinates (CIE) of the (SrBaSm)Si2O2N2: (Eu3+Ce3+) blue–green phosphors and the color conversion glass ceramics were studied in the sintering temperature range from 600 °C to 800 °C. The luminous intensity and internal quantum yield (QY) of the blue–green phosphors and glass ceramics decreased with the sintering temperature increasing. When the sintering temperature increased beyond 750 °C, the phosphors and the color conversion glass ceramics almost had no peak in photoluminescence (PL) and excitation (PLE) spectra. The results showed that the blue–green phosphors had poor thermal stability at higher temperature. The lattice structure of the phosphors was destroyed by the glass matrix and the Ce3+ in the phosphors was oxidized to Ce4+, which further caused a decrease in luminescent properties of the color conversion glass ceramics.

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Preparation and luminescence properties of Eu2+ -doped CASN-sinoite multiphase system for LED

Cited by 14 publications

References 5 publications

Local analysis of Eu²⁺emission in CaAlSiN₃

Local analysis of Eu²⁺emission in CaAlSiN₃

Phosphor-in-glass with time-evolving multicolor luminescence for dynamic anticounterfeiting

Effect of sintering temperature on luminescence properties of borosilicate matrix blue–green emitting color conversion glass ceramics*

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Preparation and luminescence properties of Eu2+ -doped CASN-sinoite multiphase system for LED

Cited by 14 publications

References 5 publications

Local analysis of Eu2+emission in CaAlSiN3

Local analysis of Eu2+emission in CaAlSiN3

Phosphor-in-glass with time-evolving multicolor luminescence for dynamic anticounterfeiting

Effect of sintering temperature on luminescence properties of borosilicate matrix blue–green emitting color conversion glass ceramics*

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Product

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Local analysis of Eu²⁺emission in CaAlSiN₃

Local analysis of Eu²⁺emission in CaAlSiN₃