Two-Site Occupancy Induced a Broad-Band Emission in Phosphor K2YZr(PO4)3:Eu2+ for White-Light-Emitting Diode Applications

In this work, carbon nanodots (CNDs) were synthesized from extract of mango leaves. Sphere nanodots were formed rapidly by one-step microwave heating. The photoluminescence (PL) of the CNDs was found greatly dependent on the reaction temperature. The emission peak position of the CNDs changed from 550[Formula: see text]nm to 430[Formula: see text]nm when the heating temperature increased from 120[Formula: see text]C to 150[Formula: see text]C. Particularly, the CNDs synthesized at 130[Formula: see text]C showed multi-band emission at 411[Formula: see text]nm, 480[Formula: see text]nm and 530[Formula: see text]nm, providing emitting color from blue to yellow. Moreover, the free chlorophyll molecules in the solution added red fluorescence at 670[Formula: see text]nm, and the integrated emitting color of the CNDs solution was close to white. Coated on a commercial 365[Formula: see text]nm light-emitting diode (LED) chip, the CNDs showed greenish white light with CIE coordinates of (0.37, 0.44). This work provided a one-pot, rapid and green method to obtain multi-emissive CNDs toward white LEDs.

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Single-composition Al3+-singly doped ZnO phosphors for UV-pumped warm white light emitting diode applications

Dalton Transactions ◽

10.1039/d1dt00971k ◽

2021 ◽

Author(s):

Do Quang Trung ◽

Nguyen Van Quang ◽

Manh Trung Tran ◽

Du Van Nguyen ◽

Nguyen Tu ◽

...

Keyword(s):

White Light ◽

Light Quality ◽

Light Emitting Diode ◽

Broad Band ◽

Visible Spectrum ◽

Next Generation ◽

Light Emitting ◽

Light Emitting Devices ◽

Warm White Light ◽

Doped Zno

The development of full-visible-spectrum phosphors is essential for next-generation light-emitting devices with better light quality. Herein, we report on a novel broad-band-emitting phosphor based on single-composition Al-doped ZnO phosphor. Under...

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Novel 12,12-Dimethyl-7,12-dihydrobenzo[a]acridine as a Deep-Blue Emitting Chromophore for OLEDs with Narrow-Band Emission and Suppressed Efficiency Roll-Off

Journal of Materials Chemistry C ◽

10.1039/d1tc03898b ◽

2021 ◽

Author(s):

Xu Qiu ◽

Lei Xu ◽

Shian Ying ◽

Xiyun Ye ◽

Pei Xu ◽

...

Keyword(s):

Broad Band ◽

Organic Light Emitting Diodes ◽

High Definition ◽

Light Emitting ◽

Broad Band Emission ◽

Band Emission ◽

Deep Blue ◽

Organic Light ◽

Display Technology ◽

High Color Purity

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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Engineering the Lattice Site Occupancy of Apatite-Structure Phosphors for Effective Broad-Band Emission through Cation Pairing

Inorganic Chemistry ◽

10.1021/acs.inorgchem.7b00310 ◽

2017 ◽

Vol 56 (10) ◽

pp. 5696-5703 ◽

Cited By ~ 12

Author(s):

Sanjith Unithrattil ◽

Ha Jun Kim ◽

Kyeong Hun Gil ◽

Ngoc Hung Vu ◽

Van Hien Hoang ◽

...

Keyword(s):

Lattice Site ◽

Broad Band ◽

Site Occupancy ◽

Apatite Structure ◽

Broad Band Emission ◽

Band Emission

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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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