scholarly journals Green Phosphors Based on 9,10-bis((4-((3,7-dimethyloctyl)oxy) phenyl) ethynyl) Anthracene for LED

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 703
Author(s):  
Xuefeng Ren ◽  
Hai Song ◽  
Jing Xiao ◽  
Hui-Juan Yu ◽  
Chi-Fang Peng ◽  
...  
Keyword(s):  
Blue Light ◽  
Light Emitting Diode ◽  
Visible Region ◽  
Green Light ◽  
Green Emission ◽  
Coupling Reactions ◽  
Light Emitting ◽  
Good Thermal Stability ◽  
Light Excitation ◽  
Bright Green

An anthracene aromatic unit was introduced into the phenylethynyl structure by a rigid acetylene linkage at the C-9 and C-10 positions via Sonogashira coupling reactions, resulting in a planar and straight-backbone molecule (9,10-bis((4-((3,7-dimethyloctyl)oxy) phenyl) ethynyl) anthracene) (BPEA). Thermogravimetric analysis demonstrated the good thermal stability of the BPEA. Photoluminescence analysis showed that a suitable expanded π-conjugation in the BPEA made its excitation band extend into the visible region, and an intense green emission was observed under blue-light excitation. A bright green light-emitting diode with an efficiency of 18.22 lm/w was fabricated by coating the organic phosphor onto a 460 nm-emitting InGaN chip. All the results indicate that BPEA is a useful green-emitting material which is efficiently excited by blue light, and therefore, that it could be applied in many fields without UV radiation.

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.

The Luminescence Properties of BaGd2(MoO4)4: Eu3+, Er3+, Yb3+ Phosphors

2010 ◽  
Vol 663-665 ◽  
pp. 137-140 ◽  
Author(s):  
Jia Yue Sun ◽  
Wei Hang Zhang ◽  
Yu Jing Lan ◽  
Hai Yan Du
Keyword(s):  
Red Light ◽  
Green Light ◽  
Green Emission ◽  
Infrared Light ◽  
Solid State Method ◽  
Light Excitation ◽  
Bright Green ◽  
State Method ◽  
Uv Excitation ◽  
Color Emission

Two-color emission phosphors BaGd2(MoO4)4: Eu3+, Er3+, Yb3+ have been synthesized by the high temperature solid-state method. The as-prepared BaGd2(MoO4)4: Eu3+, Er3+, Yb3+ phosphors can emit intense red light under 395 nm UV excitation, while it will show bright green light upon 980 nm infrared light excitation. It is found that the red emission peaks at 595 and 614 nm should be attributed to 5D0-7F1 and 5D0-7F2 transitions of Eu3+, respectively. The green emission peaks centered at 532 and 553 nm under 980 nm excitation, are attributed to Er3+ transitions from 4H11/2 -4I15/2 and 4S3/2-4I15/2, respectively.

scholarly journals Reproductive Response of Okra and Native Rosella to Long-day Treatment with Red, Blue, and Green Light-emitting Diode Lights

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1494-1497 ◽  
Author(s):  
Hiroshi Hamamoto ◽  
Keisuke Yamazaki
Keyword(s):  
Blue Light ◽  
Light Emitting Diode ◽  
Day Treatment ◽  
Red Light ◽  
Green Light ◽  
Exposure Period ◽  
Flower Bud ◽  
Light Emitting ◽  
Delayed Flowering ◽  
Red Leds

We investigated the reproductive responses of three cultivars of short-day plants to day-extension and night-break treatment with red, blue, and green light-emitting diodes (LEDs). The plants examined were all Malvaceae species: two cultivars of okra [Abelmoschus esculentus (L.) Moench.] and a cultivar of native rosella [Abelmoschus moschatus ssp. tuberosus (Span.) Borss.]. To create day extension or night break, we provided supplemental light from LED panels with peak photon emissions of 470 (blue), 520 (green), or 650 (red) nm. Day-extension treatment using red or blue LEDs inhibited flower and bud appearances; the response was especially pronounced with red LEDs. Night-break treatment with red LEDs also delayed flower bud appearance, but night break with blue LEDs did not produce a clear effect. Night break with green light delayed flowering more strongly than blue light but a little less than red light. We concluded that the dark period-regulated reproductive processes of these plants are most sensitive to disruption by red light, closely followed by green light, but that they are insensitive to blue light, especially when the exposure period is short.

n-type GaN surface etched green light-emitting diode to reduce non-radiative recombination centers

2021 ◽  
Vol 118 (2) ◽  
pp. 021102
Author(s):  
Dong-Pyo Han ◽  
Ryoto Fujiki ◽  
Ryo Takahashi ◽  
Yusuke Ueshima ◽  
Shintaro Ueda ◽  
...  
Keyword(s):  
Radiative Recombination ◽  
Light Emitting Diode ◽  
Green Light ◽  
Light Emitting ◽  
Recombination Centers

OPTICAL PROPERTIES OF GaInN/GaN MULTI-QUANTUM WELL STRUCTURE AND LIGHT EMITTING DIODE GROWN BY METALORGANIC CHEMICAL VAPOR PHASE EPITAXY

2007 ◽  
Vol 17 (01) ◽  
pp. 81-84
Author(s):  
J. Senawiratne ◽  
M. Zhu ◽  
W. Zhao ◽  
Y. Xia ◽  
Y. Li ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Well ◽  
Stark Effect ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Green Emission ◽  
Luminescence Spectroscopy ◽  
Light Emitting ◽  
Quantum Confined Stark Effect ◽  
Multi Quantum Well

Optical properties of green emission Ga 0.80 In 0.20 N/GaN multi-quantum well and light emitting diode have been investigated by using photoluminescence, cathodoluminescence, electroluminescence, and photoconductivity. The temperature dependent photoluminescence and cathodoluminescence studies show three emission bands including GaInN/GaN quantum well emission centered at 2.38 eV (~ 520 nm). The activation energy of the non-radiative recombination centers was found to be ~ 60 meV. The comparison of photoconductivity with luminescence spectroscopy revealed that optical properties of quantum well layers are strongly affected by the quantum-confined Stark effect.

scholarly journals Green-blue light-emitting platinum(ii) complexes of cyclometallated 4,6-difluoro-1,3-dipyridylbenzenes showing mesophase organisation

2015 ◽  
Vol 3 (39) ◽  
pp. 10177-10187 ◽  
Author(s):  
Valery N. Kozhevnikov ◽  
Bertrand Donnio ◽  
Benoît Heinrich ◽  
J. A. Gareth Williams ◽  
Duncan W. Bruce
Keyword(s):  
Blue Light ◽  
Green Light ◽  
Light Emitting

Blue-green light-emitting phosphorescent PtII complexes of 1,3-bis(2-pyridyl)benzene are reported that incorporate hexadecyl-containing fragments in the 5-position of the pyridine rings.

scholarly journals In vitro and in vivo Efficacy of New Blue Light Emitting Diode Phototherapy Compared to Conventional Halogen Quartz Phototherapy for Neonatal Jaundice

2005 ◽  
Vol 20 (1) ◽  
pp. 61 ◽  
Author(s):  
Yun Sil Chang ◽  
Jong Hee Hwang ◽  
Hyuk Nam Kwon ◽  
Chang Won Choi ◽  
Sun Young Ko ◽  
...  
Keyword(s):  
Blue Light ◽  
Neonatal Jaundice ◽  
Light Emitting Diode ◽  
In Vivo Efficacy ◽  
Light Emitting

Green Light Emitting Diode Irradiation Enhances Fibroblast Growth Impaired by High Glucose Level

2005 ◽  
Vol 23 (2) ◽  
pp. 167-171 ◽  
Author(s):  
Elke M. Vinck ◽  
Barbara J. Cagnie ◽  
Maria J. Cornelissen ◽  
Heidi A. Declercq ◽  
Dirk C. Cambier
Keyword(s):  
Glucose Level ◽  
High Glucose ◽  
Light Emitting Diode ◽  
Green Light ◽  
Fibroblast Growth ◽  
Light Emitting ◽  
High Glucose Level
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