Preparation of a New Red Long Afterglow Phosphor Strontium Aluminate Composition

A new red afterglow phosphor Sr3Al2O6: Eu2+, Dy3+ was synthesized by solid-state reaction and sintered at 1150°C for 2h in reducing atmosphere. Red long lasting phosphorescence of the prepared materials is observed in the dark with naked eye after the removal of the excitation light. From the photoluminescence spectra, the broad emission band centered at 612 nm is confirmed. Excitation band chiefly lies in visible range and its maximum peak is at 473nm. Luminescence mechanism is studied.

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Synthesis and Characterization of Lightweight Beryllium Chloro Silicate Phosphor

10.4018/978-1-7998-7864-3.ch004 ◽

2022 ◽

pp. 89-100

Author(s):

Khushbu Sharma

Keyword(s):

Blue Emission ◽

Emission Peak ◽

Excitation Band ◽

Photoluminescence Spectra ◽

Strong Emission ◽

White Leds ◽

Long Afterglow ◽

Silicate Phosphor ◽

Low Weight

In this chapter, low weight barium-based cholorsilicate Ba5Cl6Si2O6:Eu2+ is prepared through a solid-state reaction. To confirm the structure of the synthesized phosphors, powder photographs were obtained using an x-ray diffractometer. Photoluminescence spectra and FTIR spectra were recorded. Photoluminescence spectra are studied. The emission peak is observed at 407 nm at excitation 275 nm. The intense violet-blue emission is obtained. The broad excitation band and strong emission indicate that Ba5Cl6Si2O6:Eu2+could be a good phosphor candidate for blue LED and white LEDs. Decay curve indicates the phosphor has a long afterglow feature.

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Synthesis and Luminescent Properties of Violet-Ultraviolet Long Afterglow Phosphors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.663-665.170 ◽

2010 ◽

Vol 663-665 ◽

pp. 170-176

Author(s):

Hao Yi Wu ◽

Yi Hua Hu ◽

Yin Hai Wang ◽

Chu Jun Fu ◽

Feng Wen Kang ◽

...

Keyword(s):

Solid State ◽

Oxygen Vacancies ◽

Trap Depth ◽

Luminescent Properties ◽

Solid State Reaction Method ◽

Broad Emission Band ◽

Suitable Model ◽

Reaction Method ◽

Long Afterglow ◽

Broad Emission

The M1.99MgSi2O7: Ce3+0.01 (M: Ba, Sr, Ca) phosphors were prepared by the solid-state reaction method. All the samples emit the violet-ultraviolet light with a broad emission band from about 330 nm to 500 nm. All the phosphors samples show a long afterglow. The strongest afterglow intensity and the longest decay duration of the afterglow come from the Ca1.99MgSi2O7: Ce3+0.01 sample. It is attributed to the suitable trap depth and the high trap concentration of this sample. The traps of these phosphors are induced by the lattice defects. A suitable model involving the cation vacancies and the oxygen vacancies, which act as the hole traps and the electron traps respectively, is proposed.

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Effects of Firing Temperature and Time on the Luminescency of Phosphors in Strontium Aluminate System Co-Doped by Eu2O3 and Dy2O3 and Prepared by Solid State Reaction Processing

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.62.82 ◽

2010 ◽

Vol 62 ◽

pp. 82-87 ◽

Cited By ~ 2

Author(s):

Selvin Yesilay Kaya ◽

Bekir Karasu ◽

Guray Kaya ◽

Erkul Karacaoğlu

Keyword(s):

Electron Microscopy ◽

Firing Time ◽

Strontium Aluminate ◽

Reducing Atmosphere ◽

Long Afterglow ◽

Sintering Time ◽

Crystal Phases ◽

Reaction Processing ◽

Co Doped ◽

Scanning Electron

In the current study long afterglow phosphors in strontium aluminate system doped with Eu2+ and Dy3+ were synthesized at different firing temperatures for various time. Photoluminescency and crystallisation during sintering under reducing atmosphere were examined as functions of sintering time and temparature. XRD was employed to characterize the crystal phases of phosphors. Scanning electron microscopy (SEM) investigations were carried out to understand surface morphology and to confirm the XRD results. The optical properties of the phosphors were investigated by a phosphorescence spectrophotometer. The changes in emission and excitation spectrum were discussed accounting firing time and temperature.

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Ternary In2S3/In2O3 heterostructures and their cathodoluminescence

RSC Advances ◽

10.1039/c6ra09520h ◽

2016 ◽

Vol 6 (56) ◽

pp. 51089-51095 ◽

Cited By ~ 4

Author(s):

Wenjin Yang ◽

Baodan Liu ◽

Yujin Cho ◽

Bing Yang ◽

Benjamin Dierre ◽

...

Keyword(s):

Emission Band ◽

Three Dimensional ◽

Broad Emission Band ◽

Visible Range ◽

Broad Emission ◽

Photocatalytic Applications

Three-dimensional In2S3/In2O3 heterostructures are obtained through a CVD process. The heterostructures have a broad emission band covering the whole visible range, which holds a promise in photocatalytic applications.

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Optical Properties of CaNb2O6 Single Crystals Grown by OFZ*

Crystals ◽

10.3390/cryst11080928 ◽

2021 ◽

Vol 11 (8) ◽

pp. 928

Author(s):

Guanlin Feng ◽

Liang Li ◽

Dapeng Xu

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Single Crystals ◽

Infrared Region ◽

Broad Emission Band ◽

Floating Zone ◽

Photoluminescence Spectra ◽

Direct Transition ◽

Broad Emission

CaNb2O6 single crystals with an orthorhombic columbite structure are grown via an optical floating zone (OFZ) method. The as-grown crystals are colorless and free of low-angle grain boundaries and inclusions. They are transparent (up to 62%) in the visible to the infrared region (400–1000 nm) and have a low absorption coefficient (α = 1.56). The bandgap is determined as a direct transition and Eg = 4.28 eV. The wavelength-dependent refractive index and extinction coefficient of the CaNb2O6 crystals are derived from the obtained T and α spectra. Their photoluminescence spectra exhibit a strong and broad emission band centered at 465 nm.

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Lu3(Al,Si)5(O,N)12:Ce3+ phosphors with broad emission band and high thermal stability for white LEDs

Journal of Luminescence ◽

10.1016/j.jlumin.2014.10.032 ◽

2015 ◽

Vol 158 ◽

pp. 322-327 ◽

Cited By ~ 32

Author(s):

Jiaqing Liu ◽

Xiaojun Wang ◽

Tongtong Xuan ◽

Chunbo Wang ◽

Huili Li ◽

...

Keyword(s):

Thermal Stability ◽

Emission Band ◽

High Thermal Stability ◽

Broad Emission Band ◽

White Leds ◽

Broad Emission

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Absorption, Fluorescence and Emission Anisotropy Spectra of 4-Cyano-N,N-dimethylaniline in Different Media and at Different Temperatures

Zeitschrift für Naturforschung A ◽

10.1515/zna-1997-0506 ◽

1997 ◽

Vol 52 (5) ◽

pp. 409-414

Author(s):

A. Kawski ◽

G. Piszczek

Keyword(s):

Emission Band ◽

Effect Of Temperature ◽

Broad Emission Band ◽

Fixed Temperature ◽

Emission Anisotropy ◽

Paraffin Oil ◽

Broad Emission ◽

Negative Emission ◽

Different Temperatures ◽

Anisotropy Spectra

Abstract The effect of temperature on fluorescence and emission anisotropy spectra of 4-cyano-N,N-dimethylaniline (CDMA) was investigated in viscous (glycerol and paraffin oil) and rigid (polyvinyl alcohol) PVA and polyvinyl chloride) PVC) media. A strong effect of temperature on the intensity of a and b emission bands was observed. It was also found that the emission anisotropy, r, does not vary in the longwave emission band a at a fixed temperature but decreases in the emission band b together with the decreasing wavelength. The latter effect is due to the fact that the transition moment in this band is perpendicular to the long axis of the CDMA molecule. For CDMA in paraffin oil, a normal b band with negative emission anisotropy only occurs. In all other media used, the emission anisotropy has lower values, approaching zero, which results from the considerable covering of band b with a broad emission band a.

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Defect Characterization in ZnGeP2 by Time -Resolved Photoluminescence

MRS Proceedings ◽

10.1557/proc-450-333 ◽

1996 ◽

Vol 450 ◽

Cited By ~ 5

Author(s):

N. Dietz ◽

W. Busse ◽

H. E. Gumlich ◽

W. Ruderman ◽

I. Tsveybak ◽

...

Keyword(s):

Energy Range ◽

Infrared Emission ◽

Luminescence Spectra ◽

Broad Emission Band ◽

Wide Energy Range ◽

Time Resolved ◽

Broad Emission ◽

Donor Acceptor ◽

Donor States ◽

Time Resolved Photoluminescence

AbstractSteady state and time-resolved photoluminescence (PL) investigations on ZnGeP2 crystals grown from the vapor phase by high pressure physical vapor transport (HPVT) and from the melt by gradient freezing (GF) are reported. The luminescence spectra reveal a broad infrared emission with peak position at 1.2 eV that exhibits features of classical donor-acceptor recombination. The hyperbolic decay characteristic over a wide energy range, investigated from 1.2 eV up to 1.5eV, suggest that this broad emission band is related to one energetic recombination center. Higher energetic luminescence structures at 1.6eV and 1.7eV were revealed after annealing of ZnGeP2 crystals in vacuum for a longer period of time. The emission decay behavior in this energy range is characterized by two hyperbolic time constants, viewed as the supercomposition of the decay from the broad emission center peaked at 1.2eV and additional donor-acceptor recombination emissions at 1.6eV and 1.7eV, respectively. ZnGeP2 crystals grown under Ge-deficient conditions by HPVT show an additional emission structure at 1.8 eV with sharp emission fine structures at 1.778 eV related to the presence of additional donor states.

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