The Luminescence Properties of Green YPO4: Tb3+,Ce3+ Phosphors for WLED

2014 ◽  
Vol 989-994 ◽  
pp. 391-394
Author(s):  
Jian Li ◽  
Li Min Dong ◽  
Qin Li ◽  
Zhi Dong Han
Keyword(s):  
High Performance ◽  
Light Emitting Diode ◽  
Bath Temperature ◽  
Fourth Generation ◽  
Luminescent Material ◽  
X Ray Diffraction ◽  
Green Phosphor ◽  
Light Emitting ◽  
Structure Morphology ◽  
Co Precipitation

LED as the fourth generation light source has been extensively studied. In order to get a high-performance White Light Emitting Diode (WLED) green phosphor, YPO4:Ce3+,Tb3+ was prepared by co-precipitation. It was excited at 380nm. The structure, morphology, fluorescence property and colorimetry of the phosphors were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. Final results show the optimal concentration ratio are 1:0.05:0.01. The crystal grain of luminescent material is 200 nm. When the bath temperature is 80°C and calcined at 1000°C for 3h, the luminescence performance of the luminescent material is excellent.

Electrically driven single microribbon based near-infrared exciton-polariton light-emitting diode

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mingming Jiang ◽  
Fupeng Zhang ◽  
Kai Tang ◽  
Peng Wan ◽  
Caixia Kan
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Coherent Light ◽  
Light Emitting ◽  
Exciton Polaritons ◽  
Laser Devices

Achieving electrically-driven exciton-polaritons has drawn substantial attention toward developing ultralow-threshold coherent light sources, containing polariton laser devices and high-performance light-emitting diodes (LEDs). In this work, we demonstrate an electrically driven...

Ultraviolet light-emitting diode-assisted highly sensitive room temperature NO2 gas sensor for low-temperature solution-processed ZnO/TiO2 nanorods decorated with plasmonic Au nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Soon-Hwan Kwon ◽  
Tae-Hyeon Kim ◽  
Sang-Min Kim ◽  
Semi Oh ◽  
Kyoung-Kook Kim
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
No2 Gas Sensor ◽  
Highly Sensitive ◽  
Temperature Solution ◽  
Semiconducting Metal Oxides

Nanostructured semiconducting metal oxides such as SnO2, ZnO, TiO2, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors,...

scholarly journals Operando direct observation of spin-states and charge-trappings of blue light-emitting-diode materials in thin-film devices

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fumiya Osawa ◽  
Kazuhiro Marumoto
Keyword(s):  
Blue Light ◽  
High Performance ◽  
Density Functional ◽  
Light Emitting Diode ◽  
Green Light ◽  
Spin States ◽  
Light Emitting ◽  
Full Color ◽  
Color Displays ◽  
Materials Used

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.

Reactivity of bilirubin photoisomers on the measurement of direct bilirubin using vanadic acid method

2017 ◽  
Vol 55 (2) ◽  
pp. 296-298
Author(s):  
Hitoshi Okada ◽  
Susumu Itoh ◽  
Shohei Kawamoto ◽  
Miyo Ozaki ◽  
Takashi Kusaka
Keyword(s):  
High Performance ◽  
Light Emitting Diode ◽  
Direct Bilirubin ◽  
Acid Oxidation ◽  
Albumin Solution ◽  
Light Emitting ◽  
Oxidation Method ◽  
Before And After ◽  
Vanadic Acid ◽  
Human Serum Albumin Solution

Objective Investigation of the reactivity of fractions of bilirubin photoisomers with the vanadic acid oxidation method. Methods Bilirubin photoisomers were prepared by irradiating a bilirubin/human serum albumin solution with blue light emitting diode. Direct bilirubin and bilirubin fractions were measured using the vanadic acid oxidation method and high-performance liquid chromatography in the sample before and after irradiation. Results Direct bilirubin was increased in the solution containing bilirubin photoisomers. ( EE)-/( EZ) -cyclobilirubin-IXα and ( ZE)-/( EZ)-bilirubin-IXα completely disappeared after the addition of vanadic acid. Conclusion Bilirubin photoisomers reacted as direct bilirubin in the vanadic acid oxidation method.

Cohosts with efficient host-to-emitter energy transfer for stable blue phosphorescent organic light-emitting diodes

2021 ◽  
Author(s):  
Soo-Ghang Ihn ◽  
Eun Suk Kwon ◽  
Yongsik Jung ◽  
Jong Soo Kim ◽  
Sungho Nam ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Performance ◽  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Operating Voltage ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Low Efficiency ◽  
Blue Phosphorescent

We present a high-performance blue phosphorescent organic light-emitting diode exhibiting a low operating voltage (4.1 V), high external quantum efficiency (23.4%, at 500 cd m-2) with a low efficiency roll-off...

scholarly journals Silicon Quantum Dot Light Emitting Diode at 620 nm

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 318 ◽  
Author(s):  
Hiroyuki Yamada ◽  
Naoto Shirahata
Keyword(s):  
Quantum Dot ◽  
High Performance ◽  
Light Emitting Diode ◽  
Optically Active ◽  
Driving Voltage ◽  
Device Structure ◽  
Light Emitting ◽  
Naked Eye ◽  
Turn On ◽  
Silicon Quantum Dot

Here we report a quantum dot light emitting diode (QLED), in which a layer of colloidal silicon quantum dots (SiQDs) works as the optically active component, exhibiting a strong electroluminescence (EL) spectrum peaking at 620 nm. We could not see any fluctuation of the EL spectral peak, even in air, when the operation voltage varied in the range from 4 to 5 V because of the possible advantage of the inverted device structure. The pale-orange EL spectrum was as narrow as 95 nm. Interestingly, the EL spectrum was narrower than the corresponding photoluminescence (PL) spectrum. The EL emission was strong enough to be seen by the naked eye. The currently obtained brightness (∼4200 cd/m2), the 0.033% external quantum efficiency (EQE), and a turn-on voltage as low as 2.8 V show a sufficiently high performance when compared to other orange-light-emitting Si-QLEDs in the literature. We also observed a parasitic emission from the neighboring compositional layer (i.e., the zinc oxide layer), and its intensity increased with the driving voltage of the device.

scholarly journals High‐Performance Perovskite Light‐Emitting Diode with Enhanced Operational Stability Using Lithium Halide Passivation

2020 ◽  
Vol 59 (10) ◽  
pp. 4099-4105 ◽  
Author(s):  
Tian Wu ◽  
Junnan Li ◽  
Yatao Zou ◽  
Hao Xu ◽  
Kaichuan Wen ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diode ◽  
Operational Stability ◽  
Light Emitting
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