scholarly journals Deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics for plant lighting

2020 ◽  
Author(s):  
Zixin Wang ◽  
Hui LIN ◽  
Dawei Zhang ◽  
Yiming Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
Blue Light ◽  
Room Temperature ◽  
Solid State Reaction Method ◽  
Peak Wavelength ◽  
Blue Led ◽  
Crystal Field Strength ◽  
Light Region ◽  
Racah Parameters ◽  
Order Of Magnitude ◽  
Narrow Emission

Abstract In this study, deep red emitting Mg2TiO4:Mn4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the most efficient wavelength for photosynthesis. The crystal field strength (Dq) and the Racah parameters (B and C) are estimated by Tanabe-Sugano diagram. The thermal conductivity of the ceramics was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue light region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg2TiO4:Mn4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.

scholarly journals Deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics for plant lighting

2020 ◽  
Author(s):  
Zixin Wang ◽  
Hui Lin ◽  
Dawei Zhang ◽  
Yiming Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solid State Reaction Method ◽  
Peak Wavelength ◽  
Reaction Method ◽  
Blue Led ◽  
Crystal Field Strength ◽  
Light Region ◽  
Racah Parameters ◽  
Order Of Magnitude ◽  
Narrow Emission

Abstract In this study, deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the demanded wavelength for photosynthesis. The crystal field strength (Dq) and the Racah parameters (B and C) were estimated by the Tanabe-Sugano diagram. The thermal conductivity of the Mg2Ti(0.999)O4:0.001Mn4+ ceramic was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using the silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg2TiO4:Mn4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.

scholarly journals Deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics for plant lighting

2020 ◽  
Author(s):  
Zixin Wang ◽  
Hui LIN ◽  
Dawei Zhang ◽  
Yiming Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solid State Reaction Method ◽  
Peak Wavelength ◽  
Reaction Method ◽  
Blue Led ◽  
Crystal Field Strength ◽  
Light Region ◽  
Racah Parameters ◽  
Order Of Magnitude ◽  
Narrow Emission

Abstract In this study, deep red emitting Mg2TiO4:Mn4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the demanded wavelength for photosynthesis. The crystal field strength (Dq) and the Racah parameters (B and C) were estimated by Tanabe-Sugano diagram. The thermal conductivity of the Mg2Ti(0.999)O4: 0.001Mn4+ ceramic was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using the silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg2TiO4:Mn4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.

A novel red phosphor of Mn4+ion-doped oxyfluoroniobate BaNbOF5for warm WLED applications

CrystEngComm ◽  
2018 ◽  
Vol 20 (37) ◽  
pp. 5641-5646 ◽  
Author(s):  
Xinlong Dong ◽  
Yuexiao Pan ◽  
Dong Li ◽  
Hongzhou Lian ◽  
Jun Lin
Keyword(s):  
Blue Light ◽  
Room Temperature ◽  
Prepared Phosphor ◽  
Color Purity ◽  
Red Phosphor ◽  
Light Region ◽  
Intense Absorption ◽  
Red Luminescence

A novel red phosphor composed of Mn4+-activated oxyfluoroniobate BaNbOF5was obtained at room temperature in air. The as-prepared phosphor showed a broad and intense absorption in the blue-light region and a bright red luminescence with a color purity of 97.7%.

Luminescence Properties of Europium-Doped Yttrium Oxides Derived from Their Dodecylsulfate-Templated Mesostructure and Nanotube Forms

2003 ◽  
Vol 775 ◽  
Author(s):  
Tsuyoshi Kijima ◽  
Kenichi Iwanaga ◽  
Tomomi Hamasuna ◽  
Shinji Mohri ◽  
Mitsunori Yada ◽  
...  
Keyword(s):  
Room Temperature ◽  
Broad Band ◽  
Concentration Quenching ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Bulk Materials ◽  
Main Band ◽  
Homogeneous Precipitation Method ◽  
Order Of Magnitude ◽  
Weak Luminescence

AbstractEuropium-doped hexagonal-mesostructured and nanotubular yttrium oxides templated by dodecylsulfate species as well as surfactant free bulk oxides were synthesized by the homogeneous precipitation method. All the as grown nanostructured or bulk materials with amorphous or poorly crystalline frameworks showed weak luminescence bands at room temperature. On calcination at 1000°C these materials were converted into highly crystalline yttrium oxides, resulting in a total increase in intensity of all the bands by one order of magnitude. In the hexagonal-mesostructured system, the main band due to the 5D0-7F2 transition for the calcined phases showed a sharp but asymmetrical multiplet splitting indicating multiple Eu sites. Concentration quenching was found at a Eu content of 3 mol% or above for these phases. In contrast, the main emission for the calcined solids in the nanotubular system occurred as poorly resolved broad band and the intensity of the main band at higher Eu content was significantly enhanced compared with those for the other two systems.

Temperature Dependence of the Self-Assembled Styrene Based Random Ionomers in Aqueous Solution

2003 ◽  
Vol 775 ◽  
Author(s):  
Sung-Hwa Oh ◽  
Ju-Myung Song ◽  
Joon-Seop Kim ◽  
Hyang-Rim Oh ◽  
Jeong-A Yu
Keyword(s):  
Partition Coefficients ◽  
Room Temperature ◽  
Aqueous Media ◽  
The Self ◽  
Spectroscopic Methods ◽  
Ion Content ◽  
Repeat Units ◽  
Notable Effect ◽  
Order Of Magnitude ◽  
Experimental Errors

AbstractSolution behaviors of poly(styrene-co-sodium methacrylate) were studied by fluorescence spectroscopic methods using pyrene as a probe. The mol% of methacrylate was in the range 3.6–9.4. Water and N,N-dimethylforamide(DMF) mixture was used as a solvent (DMF/water = 0.2 mol %). The critical micelle (or aggregation) concentrations of ionomers and the partition coefficients of pyrene were obtained the temperature range 10–80°C. At room temperature, the values of CMCs (or CACs) were in the range 4.7 ×10-6 5.3 ×10-6 g/mL and we could not find any notable effect of the content of ionic repeat units within the experimental errors. Unlike CMCs, as the ion content increased, partitioning of pyrene between the hydrophobic aggregates and an aqueous media decreased from 1.5 ×105 to 9.4 ×104. As the temperature increased from 10 to 80 °C, the values of CMCs increased less than one order of magnitude. While, the partition coefficients of pyrene decreased one order of magnitude and the effect of the ion content became negligible.

Photocontrolled iodine-mediated reversible-deactivation radical polymerization with a semifluorinated alternating copolymer as the macroinitiator

2020 ◽  
Vol 11 (47) ◽  
pp. 7497-7505
Author(s):  
Jiannan Cheng ◽  
Kai Tu ◽  
Enjie He ◽  
Jinying Wang ◽  
Lifen Zhang ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Radical Polymerization ◽  
Room Temperature ◽  
Blue Led ◽  
Led Light ◽  
Alternating Copolymers ◽  
Alternating Copolymer ◽  
Reversible Deactivation ◽  
Novel Strategy ◽  
Reversible Deactivation Radical Polymerization

A novel strategy for preparing block copolymers with semifluorinated alternating copolymers as macroinitiators was established by photocontrolled iodine-mediated RDRP under irradiation with blue LED light at room temperature.

Visible-light-initiated Catalyst-free Oxidative Cleavage of Triaryl-Substituted Alkenes C=C Bonds under Ambient Conditions

2021 ◽  
Author(s):  
Wenjing Li ◽  
Shun Li ◽  
Lihua Luo ◽  
Yichen Ge ◽  
Jiaqi Xu ◽  
...  
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Ambient Air ◽  
Oxidative Cleavage ◽  
Ambient Conditions ◽  
Blue Led ◽  
Catalyst Free

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing pyridyl motif with ambient air under irradiation of blue LED at room temperature has been developed. The reaction was facile and scalable,...

scholarly journals Air stable and highly efficient Bi3+-doped Cs2SnCl6 for blue light-emitting diodes

RSC Advances ◽  
2021 ◽  
Vol 11 (42) ◽  
pp. 26415-26420
Author(s):  
Yue Yao ◽  
Si-Wei Zhang ◽  
Zijian Liu ◽  
Chun-Yun Wang ◽  
Ping Liu ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Coordinates ◽  
Blue Led ◽  
Highly Efficient ◽  
Photoluminescence Quantum Yield ◽  
Long Life

A Bi3+-doped Cs2SnCl6 exhibits photoluminescence at around 456 nm and a photoluminescence quantum yield of 31%. The blue LED based on the Bi3+-doped Cs2SnCl6 phosphor exhibits a long life of 120 hours and a CIE color coordinates of (0.14, 0.11).

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

Room temperature blue LED based on p-ZnO/(CdZnO/ZnO) MQWs/ n-ZnO

2016 ◽  
Vol 180 ◽  
pp. 204-208 ◽  
Author(s):  
Vishnu Awasthi ◽  
Sushil Kumar Pandey ◽  
Shruti Verma ◽  
Shaibal Mukherjee
Keyword(s):  
Room Temperature ◽  
Blue Led
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