scholarly journals Temperature-Dependent Luminescence of Red-Emitting Ba2Y5B5O17: Eu3+ Phosphors with Efficiencies Close to Unity for Near-UV LEDs

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 763 ◽  
Author(s):  
Egle Ezerskyte ◽  
Julija Grigorjevaite ◽  
Agne Minderyte ◽  
Sebastien Saitzek ◽  
Arturas Katelnikovas
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
White Light ◽  
Light Sources ◽  
Phosphor Powder ◽  
Temperature Dependent ◽  
Blue Led ◽  
Uv Led ◽  
Uv Leds

Solid state white light sources based on a near-UV LED chip are gaining more and more attention. This is due to the increasing efficiency of near-UV-emitting LED chips and wider phosphors selection if compared to devices based on blue LED chips. Here, a brief overview is given of the concepts of generating white light employing near-UV LED and some optical properties of the available phosphors are discussed. Finally, the synthesis and optical properties of very efficient red-emitting Ba2Y5B5O17:Eu3+ phosphor powder and ceramics is reported and discussed in terms of possible application as a red component in near-UV LED-based white light sources.

Bandgap trimming and optical properties of Si3N4:Al microbelt phosphors for warm white light-emitting diodes

CrystEngComm ◽  
2019 ◽  
Vol 21 (43) ◽  
pp. 6566-6573
Author(s):  
Dongyi Shen ◽  
Yiran Shao ◽  
Yingchun Zhu
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
White Light ◽  
Light Emitting Diodes ◽  
Bandgap Energy ◽  
Light Emitting ◽  
Warm White Light ◽  
Yellow Orange ◽  
White Light Emitting Diodes ◽  
Blue Chip

The bandgap energy of Si3N4:Al is precisely and gradually tailored from 2.58 to 2.85 eV by increasing the Al concentration. Si3N4:Al:Eu phosphors exhibiting a yellow-orange emission are promising for solid-state warm white lighting under blue chip excitation.

Photoluminescence properties of single-component white-emitting Ca9Bi(PO4)7:Ce3+,Tb3+,Mn2+phosphors for UV LEDs

2015 ◽  
Vol 3 (27) ◽  
pp. 7096-7104 ◽  
Author(s):  
Kai Li ◽  
Mengmeng Shang ◽  
Yang Zhang ◽  
Jian Fan ◽  
Hongzhou Lian ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
White Light ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Reaction Method ◽  
White Light Emitting Diodes ◽  
Uv Leds ◽  
Uv Excitation

A series of Ca9Bi(PO4)7:Ce3+,Tb3+,Mn2+phosphors synthesizedviathe high-temperature solid-state reaction method can emit intense tunable color from purple-blue to red including white under UV excitation, which shows their potential application in UV-pumped white-light-emitting diodes.

scholarly journals Towards Multi-Functional SiO2@YAG:Ce Core–Shell Optical Nanoparticles for Solid State Lighting Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 153 ◽  
Author(s):  
Mahdi Kiani Khouzani ◽  
Abbas Bahrami ◽  
Maryam Yazdan Mehr ◽  
Willem Dirk van Driel ◽  
Guoqi Zhang
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
White Light ◽  
Sio2 Nanoparticles ◽  
Solid State Lighting ◽  
Core Shell ◽  
Yellow Light ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Core Shell Nanoparticles

This paper aims to investigate the synthesis, structure, and optical properties of SiO2@YAG:Ce core–shell optical nanoparticles for solid state lighting applications. YAG:Ce phosphor is a key part in white light emitting diodes (LEDs), with its main functionality being the generation of yellow light. Generated yellow light from phosphor will be combined with blue light, emitted from chip, resulting in the generation of white light. Generated light in LEDs will often be scattered by SiO2 nanoparticles. SiO2 nanoparticles are often distributed within the optical window, aiming for a more homogeneous light output. The main idea in this research is to combine these functionalities in one core–shell particle, with its core being SiO2 and its shell being phosphor. In this study core–shell nanoparticles with different Ce3+ concentrations were synthesized by a sol–gel method. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), small angle X-ray scattering (SAXS) analysis, high resolution transmission electron macroscopy (HRTEM), Fourier transform infrared (FTIR), and photoluminescence spectroscopy. Luminescence characteristics of SiO2@YAG:Ce core–shell particles were compared with that of SiO2/YAG:Ce mixture composite, which is now used in commercial LEDs. Obtained results showed that core–shell nanoparticles have comparatively much better optical properties, compared to SiO2/YAG:Ce mixture composite and can therefore be potentially used in LEDs.

scholarly journals Multiband photoluminescence from carbon nanoflakes synthesized by hot filament CVD: towards solid-state white light sources

2014 ◽  
Vol 2 (16) ◽  
pp. 2851-2858 ◽  
Author(s):  
B. B. Wang ◽  
K. Ostrikov ◽  
K. Zheng ◽  
L. Wang ◽  
S. S. Zou
Keyword(s):  
Chemical Vapor Deposition ◽  
Solid State ◽  
White Light ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
Light Sources ◽  
Hot Filament Cvd ◽  
Carbon Nanoflakes ◽  
Hot Filament

Carbon nanoflakes (CNFLs) are synthesized on silicon substrates deposited with carbon islands in a methane environment using hot filament chemical vapor deposition.

The Application of UV-LEDs to Microlithography

2008 ◽  
Author(s):  
Chen-Kang Huang ◽  
Jeng-Gang Sung
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Light Sources ◽  
Light Emitting ◽  
Uv Led ◽  
Line Process ◽  
Point Light ◽  
The Cost ◽  
Uv Leds ◽  
Light Beams

Benefited by the progress of material science, Light-Emitting Diodes (LED) with UV-emitting have been produced successfully. Like other LEDs, UV-LEDs exhibit several advantages, such as energy conservation, long life, compact, and quick response. The UV-LED application to microlithography is attractive. In contrast to point light sources requiring lens to generate parallel light beams, an array of UV-LEDs can emit nearly parallel light beams easily. UV-LEDs only need 3 to 4 voltages to ignite, which is much lower than that required by mercury short arc lamps. The cost of using UV-LEDs is also much lower than current solutions. In this study, we used UV-LEDs as the light source in the laboratory lithography system. LEDs, whose emitting spectrum distributed between 370 to 410 nm mostly, were displaced on the bottom of a heat sink. Two 10-by-10 cm2 test masks, where the smallest pattern was 20 μm, were used to examine the resolution ability of this combination. Each light module was utilized to exposure photosensitized printed circuit board (PCB). After etching, the printed patterns were observed under microscope. The minimum reproducible feature size was 100 μm. Through the 4” mask, the uniformity was decent, and could be improved by using LEDs from the same batch, collimator, or LED displacement optimization. In the future, standard g-line process can be performed, and further tests will be performed to check the limits of the UV-LED system. Based on these preliminary tests, it seems like the usage of UV-LEDs should be a feasible solution for microlithography.

scholarly journals Design and Performance of Nitride-based UV LEDs

2000 ◽  
Vol 622 ◽  
Author(s):  
M. H. Crawford ◽  
J. Han ◽  
R. J. Shul ◽  
M. A. Banas ◽  
J. J. Figiel ◽  
...  
Keyword(s):  
Quantum Well ◽  
High Efficiency ◽  
Active Regions ◽  
Temperature Dependent ◽  
Optical Efficiency ◽  
Uv Led ◽  
And Performance ◽  
Photoluminescence Studies ◽  
Uv Leds ◽  
Internal Absorption

ABSTRACTWe overview several of the challenges in achieving high efficiency nitride-based UV (< 400 nm) LEDs. The issue of optical efficiency is presented through temperature-dependent photoluminescence studies of various UV active regions. These studies demonstrate enhanced optical efficiencies for active regions with In-containing alloys ( InGaN, AlInGaN). We compare the performance of two distinct UV LED structures. GaN/AlGaN quantum well LEDs with λ < 360 nm emission have demonstrated output powers > 0.1 mW, but present designs suffer from internal absorption effects. InGaN/AlInGaN quantum well LEDs with 370 nm< λ < 390 nm emission and > 1 mW output power are also presented.

A set of manganese ion activated fluoride phosphors (A2BF6:Mn4+, A = K, Na, B = Si, Ge, Ti): synthesis below 0 °C and efficient room-temperature photoluminescence

2016 ◽  
Vol 4 (40) ◽  
pp. 9561-9568 ◽  
Author(s):  
Fei Tang ◽  
Zhicheng Su ◽  
Honggang Ye ◽  
Mingzheng Wang ◽  
Xin Lan ◽  
...  
Keyword(s):  
Solid State ◽  
Transition Metal ◽  
White Light ◽  
Metal Ion ◽  
Room Temperature ◽  
Light Sources ◽  
Transition Metal Ion ◽  
Room Temperature Photoluminescence ◽  
Manganese Ion

Transition-metal ion activated solid-state phosphors are of particular interest for the development of LED-based white light sources.

scholarly journals Size- and Temperature-Dependent Intraband Optical Properties of Heavily n-Doped PbS Colloidal Quantum Dot Solid-State Films

ACS Nano ◽  
2020 ◽  
Vol 14 (6) ◽  
pp. 7161-7169 ◽  
Author(s):  
Iñigo Ramiro ◽  
Biswajit Kundu ◽  
Mariona Dalmases ◽  
Onur Özdemir ◽  
María Pedrosa ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Quantum Dot ◽  
Temperature Dependent ◽  
Colloidal Quantum Dot
Sign in / Sign up

Export Citation Format

Share Document