Broad-band emission from a multiple asymmetric quantum-well light-emitting diode

The fabrication of deep-blue emitting materials with high color purity is crucial for the realization of ultra-high-definition display technology based on organic light-emitting diodes (UHD-OLEDs). However, the intrinsic broad-band emission...

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Optimization of Cerium Doped Garnets Using Combinatorial Chemistry for Application as Luminescent Conversion Phosphors in White LEDs

MRS Proceedings ◽

10.1557/proc-560-65 ◽

1999 ◽

Vol 560 ◽

Cited By ~ 6

Author(s):

Jennifer L. Wu ◽

Martin Devenney ◽

Earl Danielson ◽

Damadora Poojary ◽

Henry Weinberg

Keyword(s):

Broad Band ◽

Solution Chemistry ◽

Combinatorial Approach ◽

Light Emitting ◽

White Leds ◽

Broad Band Emission ◽

Band Emission ◽

Traditionally Prepared ◽

Powder Samples ◽

Visible Wavelengths

ABSTRACTAn area of considerable research interest is the development of visible light, down- conversion phosphors for application in white light emitting diodes (LEDs). In such devices, a blue LED can act as the primary light source, exciting photoluminescence in a phosphor with subsequent broad band emission occurring at visible wavelengths of lower energy. A combinatorial approach to synthesize and screen potential inorganic phosphors for such an application has been developed. Using solution chemistry techniques, solid state thin film arrays of (Y1−xGdx)3-z(Al1−yGay)5O12:Ce3+Z, where x and y range from 0 to 1.0 and z is equal to 0.03 were synthesized. Subsequent characterization demonstrates that the combinatorial approach can be used to rapidly screen potential phosphors for use as luminescence down-converters in white LEDs. Emission and excitation trends match those reported in the literature for traditionally prepared powder samples. The optimal Ce3+ concentration in Y3Al5O12 (YAG) was identified as approximately 1.5 mol%, and within the YAG-substituted host specific compositions were identified as promising blue to yellow phosphor candidates.

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Spectral Properties of Various Cerium Doped Garnet Phosphors for Application in White GaN-based LEDs

MRS Proceedings ◽

10.1557/proc-658-gg11.8 ◽

2000 ◽

Vol 658 ◽

Author(s):

Jennifer L. Wu ◽

Steven P. Denbaars ◽

Vojislav Srdanov ◽

Henry Weinberg

Keyword(s):

Spectral Properties ◽

Broad Band ◽

Solution Chemistry ◽

X Ray Diffraction ◽

Light Emitting ◽

Garnet Phase ◽

Broad Band Emission ◽

Band Emission ◽

Traditionally Prepared ◽

White Light Emitting Diodes

ABSTRACTRecently, a renewed research interest has emerged for the development of visible light, down-converting phosphors for application in white light emitting diodes (LEDs). In such devices, a blue GaN LED can act as the primary light source, exciting photoluminescence in a phosphor with subsequent broad-band emission occurring at lower energies. It was recently reported that use of a combinatorial approach to synthesize and screen potential inorganic phosphors for such an application could aid in identifying improved phosphors for blue to yellow down conversion. Using solution chemistry techniques developed by Symyx Technologies, solid state thin-film arrays (libraries) based on the garnet structure (A1-xBx)3(C1-yDy)5O12:Ce3+, where x and y = 0 to 1.0 and A, B = Y, Gd, or Lu; C., D = Al or Ga, were synthesized. X-ray diffraction was used to select library samples of the crystalline garnet phase. Libraries of these various garnets were then characterized, and their spectral properties compared to traditionally prepared bulk powder phosphors of similar composition. Emission and excitation trends show that as larger cations are substituted for Y (A = Y), emission and excitation are red-shifted and as larger cations are substituted for Al (C = Al), emission and excitation are blue-shifted. If smaller cations are substituted for Y and Al, an opposite trend is observed.

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Fabrication of Electroluminescence Device for PEDOT:PSS / ploy TPD/Eu2O3 Nanoparticles junction

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v17i43.484 ◽

2019 ◽

Vol 17 (43) ◽

pp. 33-40

Author(s):

Hussein Riyadh Mohammed

Keyword(s):

Energy Gap ◽

Light Emitting Diode ◽

Red Light ◽

Broad Band ◽

Phase Segregation ◽

Europium Oxide ◽

Color Temperature ◽

Inorganic Semiconductors ◽

Broad Band Emission ◽

Band Emission

We manufactured the nanoparticles light emitting diode (NPs-LED) for organic and inorganic semiconductors to achieve electroluminescence (EL). The nanoparticles of Europium oxide(Eu2O3) were incorporated into the thin film layers of the organic compounds, poly(3,4,- ethylene dioxythiophene)/polystyrene sulfonic acid (PEDOT:PSS), N,N’–diphenyl-N,N’ –bis(3-methylphenyl)-1,1’-biphenyl 4,4’- diamine (poly TPD) and polymethyl methacrylate (PMMA), by the spin coating and with the help of the phase segregation method. The EL of NPs-LED, was study for the different bias voltages (20, 25, 30) V at the room temperature, from depending on the CIE 1931 color spaces and it was generated the white light at 20V, the orange light generation at 25Vand the red light at 30 V. That by benefit from transition between deep levels in energy gap for Eu2O3 NPs (surface state) and magnetic dipole states for Eu+ (5D0-3 and5L6 to 7F0-6). The Current – Voltage (I-V) Behavior demonstrate that the current comparative with the voltage was good and the knee voltage was 5 V. The EL spectrum shows a broad band emission, the range from EL 350 - 700 nm. Finally, the range of correlated color temperature (CCT) it was between (1200 to 4000).

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Cyan Broad-Band Emission Phosphor with Scandium Silicon Multiple-Ring Structure for White Light-Emitting Diodes and Field Emission Displays

Inorganic Chemistry ◽

10.1021/acs.inorgchem.1c00773 ◽

2021 ◽

Author(s):

Yuhan Zhou ◽

Hang Chen ◽

Yuhua Wang

Keyword(s):

Field Emission ◽

White Light ◽

Light Emitting Diodes ◽

Broad Band ◽

Ring Structure ◽

Light Emitting ◽

Broad Band Emission ◽

Band Emission ◽

Field Emission Displays ◽

White Light Emitting Diodes

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The challenging SED of AP Librae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312009532 ◽

2011 ◽

Vol 7 (S284) ◽

pp. 411-413 ◽

Cited By ~ 3

Author(s):

David Sanchez ◽

Berrie Giebels ◽

Pascal Fortin ◽

Keyword(s):

Spectral Energy Distribution ◽

Broad Band ◽

Low Frequency ◽

Theoretical Models ◽

Intermediate Frequency ◽

High Energy ◽

Spectral Energy ◽

Broad Band Emission ◽

Band Emission ◽

Bl Lac

AbstractMatching the broad-band emission of active galaxies with the predictions of theoretical models can be used to derive constraints on the properties of the emitting region and to probe the physical processes involved. AP Librae is the third low frequency peaked BL Lac (LBL) detected at very high energy (VHE, E>100GeV) by an Atmospheric Cherenkov Telescope; most VHE BL Lacs (34 out of 39) belong to the high-frequency and intermediate-frequency BL Lac classes (HBL and IBL). LBL objects tend to have a higher luminosity with lower peak frequencies than HBLs or IBLs. The characterization of their time-averaged spectral energy distribution is challenging for emission models such as synchrotron self-Compton (SSC) models.

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Microscintillator of Ce Doped β-NaLuF4 in Uniform Hexagonal Prism Morphology by a Facile Hydrothermal Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.541-542.220 ◽

2014 ◽

Vol 541-542 ◽

pp. 220-224

Author(s):

Li Sha Liu ◽

Hao Hong Chen ◽

Bi Qiu Liu ◽

Bin Tang ◽

Zhi Jia Sun ◽

...

Keyword(s):

Hydrothermal Method ◽

Hexagonal Phase ◽

Broad Band ◽

High Energy ◽

Hexagonal Prism ◽

Facile Hydrothermal Method ◽

X Ray ◽

Strong Broad Band ◽

Broad Band Emission ◽

Band Emission

To explore micro-or nanoscintillator with a controllable architecture, a novel facile hydrothermal method easy for commercial run was used to synthesize pure and Ce doped β-NaLuF4 microcrystals at 453K. The morphology of uniform hexagonal prism with 3.3μm in diameter and 1.4 μm in thickness, respectively, is presented by the results of scanning electron microscopy (SEM). Powder X-ray diffraction (PXRD) patterns show the products are both pure hexagonal phase. Different from the undoped product without any irradiation, the Ce doped product has given strong broad band emission attributed to 5d4f transition of Ce3+, which can be potentially used as scintillator for biomedical imaging and detectors for high energy such as X-ray and γray. This synthetical strategy extends the understanding about nanomaterial chemistry and can be also useful for other systems such as fluorides, oxides and sulfides.

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OPTICAL PROPERTIES OF GaInN/GaN MULTI-QUANTUM WELL STRUCTURE AND LIGHT EMITTING DIODE GROWN BY METALORGANIC CHEMICAL VAPOR PHASE EPITAXY

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156407004266 ◽

2007 ◽

Vol 17 (01) ◽

pp. 81-84

Author(s):

J. Senawiratne ◽

M. Zhu ◽

W. Zhao ◽

Y. Xia ◽

Y. Li ◽

...

Keyword(s):

Optical Properties ◽

Quantum Well ◽

Stark Effect ◽

Light Emitting Diode ◽

Chemical Vapor ◽

Green Emission ◽

Luminescence Spectroscopy ◽

Light Emitting ◽

Quantum Confined Stark Effect ◽

Multi Quantum Well

Optical properties of green emission Ga 0.80 In 0.20 N/GaN multi-quantum well and light emitting diode have been investigated by using photoluminescence, cathodoluminescence, electroluminescence, and photoconductivity. The temperature dependent photoluminescence and cathodoluminescence studies show three emission bands including GaInN/GaN quantum well emission centered at 2.38 eV (~ 520 nm). The activation energy of the non-radiative recombination centers was found to be ~ 60 meV. The comparison of photoconductivity with luminescence spectroscopy revealed that optical properties of quantum well layers are strongly affected by the quantum-confined Stark effect.

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