Luminescence Tuning, Thermal Quenching, and Electronic Structure of Narrow-Band Red-Emitting Nitride Phosphors

2017 ◽  
Vol 56 (19) ◽  
pp. 11837-11844 ◽  
Author(s):  
Dianpeng Cui ◽  
Zhen Song ◽  
Zhiguo Xia ◽  
Quanlin Liu
Keyword(s):  
Electronic Structure ◽  
Narrow Band ◽  
Thermal Quenching

THE EFFECT OF 3dn IMPURITIES IN THE YBa2Cu3O7−δ SUPERCONDUCTOR

1993 ◽  
Vol 07 (22) ◽  
pp. 1449-1456
Author(s):  
G. A. R. LIMA ◽  
VITOR TORRES ◽  
A. FAZZIO
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Atomic Number ◽  
Configuration Interaction ◽  
Narrow Band ◽  
Correlation Effects ◽  
Chemical Trends

The electronic structure of the CuO chain and the CuO 2 plane in the superconductor YBa 2 Cu 3 O 7−δ doped with 3dn transition-metal (TM) atoms are investigated. The calculations were performed through the semiempirical INDO/S technique, where the correlation effects are taken into account by the Configuration Interaction (CI) procedure. We also calculated, for all 3dn impurities, the Hubbard parameters Udd corresponding to a narrow band. The results obtained demonstrate clear chemical trends in the electronic structure of the 3d's, from Ti to Ni, when they substitute Cu(1) and Cu(2) sites; the hybridization decreases when the atomic number Z decreases. Our work provides a picture which is important to understand the change in T c when the host is doped with TM atom.

A narrow-band blue emitting phosphor Ca8Mg7Si9N22:Eu2+ for pc-LEDs

2019 ◽  
Vol 7 (13) ◽  
pp. 3730-3734 ◽  
Author(s):  
Chao Li ◽  
Xiao-Ming Wang ◽  
Feng-Feng Chi ◽  
Zu-Pei Yang ◽  
Huan Jiao
Keyword(s):  
Emission Intensity ◽  
Room Temperature ◽  
Narrow Band ◽  
Blue Emission ◽  
Thermal Quenching ◽  
Unit Cell ◽  
Photoluminescence Emission ◽  
Space Group

Ca8Mg7Si9N22 crystallizes in a tetragonal space group P42/nmc (No. 137) with a unit cell of a = 7.3271(11) Å and c = 10.336(2) Å. Ca8Mg7Si9N22:Eu2+ shows a narrow-band blue emission peaking at 400 nm with an intriguing bandwidth ∼34 nm and shows remarkably high thermal quenching resistance, maintaining 92% photoluminescence emission intensity at 420 K and 75% at 700 K of that measured at room temperature.

Electronic Structure of an [FeFe] Hydrogenase Model Complex in Solution Revealed by X-ray Absorption Spectroscopy Using Narrow-Band Emission Detection

2012 ◽  
Vol 134 (34) ◽  
pp. 14142-14157 ◽  
Author(s):  
Nils Leidel ◽  
Petko Chernev ◽  
Kajsa G. V. Havelius ◽  
Lennart Schwartz ◽  
Sascha Ott ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectroscopy ◽  
Narrow Band ◽  
X Ray ◽  
Band Emission ◽  
Model Complex ◽  
Emission Detection ◽  
X Ray Absorption

scholarly journals Controlling Eu2+ Substitution towards a Narrow-Band Green-Emitting Borate Phosphor NaBaB9O15:Eu2+

2019 ◽  
Author(s):  
Ya Zhuo ◽  
Jiyou Zhong ◽  
Jakoah Brgoch
Keyword(s):  
Narrow Band ◽  
Thermal Quenching ◽  
Green Emission ◽  
Wide Band ◽  
Trap States ◽  
Wide Band Gap ◽  
Green Phosphor ◽  
Synthesis Conditions ◽  
High Connectivity ◽  
Display Systems

Highly efficient, thermally stable, narrow-band phosphors that can be excited by a blue LED chip are crucial for energy-efficient light bulbs and display lighting. Here, a rare narrow-band, green-emitting phosphor based on the compound NaBaB<sub>9</sub>O<sub>15</sub>:Eu<sup>2+</sup> is demonstrated. The emission peak is centered at 515 nm with a full-width at half-maximum (fwhm) of 61 nm (2294 cm<sup>−1</sup>), and a photoluminescence quantum yield of >80% using blue or near-UV LED excitation. This borate’s remarkable green emission stems from Eu<sup>2+</sup> substituting on the smaller [NaO<sub>6</sub>] polyhedron instead of the larger and more favorable [BaO<sub>9</sub>] polyhedron. The phosphor also exhibits negligible thermal quenching up to 650 K owing to the wide band gap, high connectivity of the rigid NaBaB<sub>9</sub>O<sub>15</sub> crystal structure, and the depopulation of trap-states. This combination of optical properties and its straightforward synthesis conditions makes NaBaB<sub>9</sub>O<sub>15</sub>:Eu<sup>2+</sup> an ideal green phosphor for next-generation LED-based lighting or display systems.

Electronic Structure and Transport Properties of CoSb3: A Narrow Band-Gap Semiconductor

1998 ◽  
Vol 545 ◽  
Author(s):  
J. O. Sofo ◽  
G. D. Mahan
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Fermi Surface ◽  
Band Gap ◽  
Narrow Band ◽  
Transport Coefficients ◽  
Electronic States ◽  
Energy Bands ◽  
Effective Masses ◽  
Hall Effect Measurements

AbstractWe report calculations which show that the band structure of CoSb3 is typical of a narrow band-gap semiconductor. The gap is strongly dependent on the relative position of the Sb atoms inside the unit cell. We obtain a band gap of 0.22 eV after minimization of these position. This value is more than four times larger than the result of a previous calculation which reported that the energy bands near the Fermi surface are unusual. The electronic states close to the Fermi level are properly described by a two-band Kane Model. The calculated effective masses and band gap are in excellent agreement with Shubnikov de Haas and Hall effect measurements. Recent measurements of the transport coefficients of this compound can be understood assuming it is a narrow band gap semiconductor, in agreement with our results.

scholarly journals Thermal quenching properties of narrow-band blue-emitting MBe2(PO4)2:Eu2+ (M = Ca, Sr) phosphors towards backlight display applications

2020 ◽  
Vol 7 (14) ◽  
pp. 2685-2691
Author(s):  
Tao Hu ◽  
Yan Gao ◽  
Xiaohong Ji ◽  
Zhiguo Xia ◽  
Qinyuan Zhang
Keyword(s):  
Narrow Band ◽  
Thermal Quenching ◽  
Selection Of

Narrow-band blue-emitting MBe2(PO4)2:Eu2+ (M = Ca, Sr) phosphors were developed via selection of an ordered host with confined doping sites.

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