A warm-white light-emitting diode (LED) without blending of different kinds of phosphors is demonstrated. An approach that consists of a blue LED chip and a wavelength-conversion phosphor is carried out. The phosphor is a newly developed yellowish orange CaEuSiAlON ceramic phosphor with high efficiency. The CIE1931 chromaticity coordinates (x, y) are (0.458, 0.414), the color temperature is 2750 K, and the luminous efficacy of this LED is 25.9 lm/W at room temperature and with a forward-bias current of 20 mA. The chromaticity of the assembled LED is more thermally stable than that of a LED with a conventional oxide phosphor (YAG:Ce) because of the better thermal stability of the oxynitride phosphor.
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http://dx.doi.org/10.1364/ol.29.002001 | DOI Listing |
Dalton Trans
January 2025
Northwest Institute for Nonferrous Metal Research, Xi'an 710016, China.
Exploring new photoexcited phosphors has attracted attention for improving the performance of white LEDs. Here, an NaBaAlBOCl:Eu phosphor with high color purity (94.11%) has been synthesized.
View Article and Find Full Text PDFLangmuir
October 2024
School of Electronic Engineering, Heilongjiang University, Harbin, Heilongjiang 150080, China.
We synthesized carbon quantum dots (CQDs) using a solvothermal method with -phenylenediamine as the carbon and nitrogen source. The sample was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. When we continued the optical characterization of the CQDs, we were surprised to discover that the colors of the synthesized CQDs changed with the dilution of the original solution.
View Article and Find Full Text PDFDalton Trans
October 2024
Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, P. R. China.
In recent years, rare-earth-based phosphors for near-ultraviolet (NUV)-triggered white light emitting diodes (w-LEDs) have become a research hotspot. However, it is still not possible to obtain phosphors with high quantum yield, excellent color purity and multiple applications. Hence, a series of novel Eu-activated CaGaGeO (CGG) red-emitting phosphors with high quantum efficiency, excellent color purity and good thermal stability were prepared by a high-temperature solid-phase method.
View Article and Find Full Text PDFInorg Chem
September 2024
School of Mechanical and Energy Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, China.
This article describes a new kind of afterglow material, ScBaZnGaO:Bi, which was synthesized through a high-temperature solid-phase method. Its crystal structure, photoluminescent characteristics, and afterglow characteristics were studied and analyzed. Upon excitation at 344 nm, ScBaZnGaO:Bi exhibits broadband emission with a central wavelength located at 571 nm (fwhm = 172.
View Article and Find Full Text PDFInorg Chem
August 2024
Hubei Key Laboratory of Plasma Chemistry and Advanced Materials & Key Laboratory of Green Chemical Engineering Process of Ministry of Education, Wuhan Institute of Technology, 430205 Wuhan, China.
The olivine-based gallate CaYGaO (CYG) with unique cationic ordering, rich lattice sites, and self-photoluminescence (PL) is suitable for application as a host of phosphor. However, research in this area is still in its early stages, especially in high-quality full-spectrum white lighting. Herein, novel CYG: Bi/Eu with a controllable PL property is designed based on energy transfer and superposition of emissions from blue self-PL, blue PL of Bi, and red-PL of Eu.
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