Analysis of circadian properties and healthy levels of blue light from smartphones at night DOI Creative Commons

Ji Hye Oh,

Heeyeon Yoo,

Hoo Keun Park

et al.

Scientific Reports, Journal Year: 2015, Volume and Issue: 5(1)

Published: June 18, 2015

Abstract This study proposes representative figures of merit for circadian and vision performance healthy efficient use smartphone displays. The recently developed luminous efficacy radiation (CER) illuminance (CIL) related to human health rhythm were measured compare three kinds commercial CIL values social network service (SNS) messenger screens from all displays higher than 41.3 biolux (blx) in a dark room at night the highest value reached 50.9 blx. These corresponded melatonin suppression (MSVs) 7.3% 11.4%, respectively. Moreover, bright had much MSV (58.7 ~ 105.2 blx 15.4 36.1%, respectively). also analyzed nonvisual visual optical properties while varying distance between screen eye controlling brightness setting. Finally, method possibly attenuate unhealthy effects was proposed investigated by decreasing emitting wavelength blue LEDs LCD backlight subsequently reducing effect display.

Language: Английский

Advanced red phosphors for white light-emitting diodes DOI
Junhao Li, Jing Yan, Dawei Wen

et al.

Journal of Materials Chemistry C, Journal Year: 2016, Volume and Issue: 4(37), P. 8611 - 8623

Published: Jan. 1, 2016

White light-emitting diodes (WLEDs) with high luminous brightness, low energy consumption, long lifetime and environmental friendliness can be applied in various fields. In order to improve the quality of white light, red phosphors are necessary.

Language: Английский

Citations

425

A single Eu2+-activated high-color-rendering oxychloride white-light phosphor for white-light-emitting diodes DOI Creative Commons
Pengpeng Dai, Cong Li, Xintong Zhang

et al.

Light Science & Applications, Journal Year: 2016, Volume and Issue: 5(2), P. e16024 - e16024

Published: Feb. 12, 2016

Single-phased, high-color-rendering index (CRI) white-light phosphors are emerging as potential phosphor-converted white-light-emitting diodes (WLEDs) and an alternative to blends of tricolor phosphors. However, it is a challenge create high CRI white light from single-doped activator. Here, we present (Ra = 91) phosphor, Sr5(PO4)3-x(BO3)xCl:Eu2+, composed Sr5(PO4)3Cl the beginning member Sr5(BO3)3Cl end member. This work utilized solid-solution method, tunable Eu2+ emission was achieved. Color-tunable emissions in response structural variation were observed Sr5(PO4)3-x(BO3)xCl solid solutions. further confirmed using X-ray Rietveld refinement, electron paramagnetic resonance spectroscopy, photoluminescence spectra. The color-tunable included that originated combination blue Sr5(PO4)3Cl:Eu2+ induced yellow at approximately 550 nm solution. Importantly, showed greater R9 90.2 under excitation 365 nm. result has rarely been reported literature than (R9 14.3) commercial Y3Al5O12:Ce3+-based WLEDs. These findings demonstrate great Sr5(PO4)3-x(BO3)xCl:0.04Eu2+ phosphor for near-UV results also provide shortcut developing single Eu2+-doped compound.

Language: Английский

Citations

317

Recent development in phosphors with different emitting colors via energy transfer DOI
Kai Li, Mengmeng Shang,

Hongzhou Lian

et al.

Journal of Materials Chemistry C, Journal Year: 2016, Volume and Issue: 4(24), P. 5507 - 5530

Published: Jan. 1, 2016

A series of recent energy transfer phosphor systems with different and controllable emission colors have been summarized in this article.

Language: Английский

Citations

313

Lanthanide Ion Codoped Emitters for Tailoring Emission Trajectory and Temperature Sensing DOI

Shu‐Na Zhao,

Lei‐Jiao Li, Xue‐Zhi Song

et al.

Advanced Functional Materials, Journal Year: 2015, Volume and Issue: 25(9), P. 1463 - 1469

Published: Jan. 27, 2015

A series of lanthanide metal‐organic frameworks (Ln‐MOFs) are synthesized through solvothermal conditions with 1,3‐bis(4‐carboxyphenyl)imidazolium (H 2 L). Owing to the contraction effect, two different types Ln‐MOFs, namely, {[Ln(L) (OH)]·3H O} n (Ln:Pr, Nd, Sm) and (COO)(H O) ]·H (Ln: Eu, Gd, Tb, Dy, Tm, Yb, Y), their corresponding codoped Ln‐MOFs Eu x Tb 1‐ L obtained. With careful adjustment relative concentration ions excitation wavelength, color luminescence can be systematically modulated white light emission further successfully achieved. Furthermore, by virtue temperature‐dependent luminescent behavior, 0.2 0.8 allows for design a thermometer an excellent linear response temperature over wide range, from 40 300 K. This work highlights practical applications tailoring fluorescent even obtaining emission, especially sensing as thermometers in single framework controlling ways.

Language: Английский

Citations

279

Full-visible-spectrum lighting enabled by an excellent cyan-emitting garnet phosphor DOI
Jia Liang, Balaji Devakumar,

Liangling Sun

et al.

Journal of Materials Chemistry C, Journal Year: 2020, Volume and Issue: 8(14), P. 4934 - 4943

Published: Jan. 1, 2020

Cyan-emitting Ca2YHf2Al3O12:xCe3+ garnet phosphors with a high photoluminescence quantum efficiency of up to 89.5% were developed for fabricating color rendering warm-white LEDs.

Language: Английский

Citations

255

Sr2Y8(SiO4)6O2:Bi3+/Eu3+: a single-component white-emitting phosphor via energy transfer for UV w-LEDs DOI
Kai Li, Jian Fan, Mengmeng Shang

et al.

Journal of Materials Chemistry C, Journal Year: 2015, Volume and Issue: 3(38), P. 9989 - 9998

Published: Jan. 1, 2015

A series of tunable blue-green to white phosphors, Sr2Y8(SiO4)6O2:Bi3+,Eu3+phosphors, preparedviaa Pechini-type sol–gel method have been investigated.

Language: Английский

Citations

219

III-Nitride nanowire optoelectronics DOI

Songrui Zhao,

Hieu Pham Trung Nguyen, Md Golam Kibria

et al.

Progress in Quantum Electronics, Journal Year: 2015, Volume and Issue: 44, P. 14 - 68

Published: Nov. 1, 2015

Language: Английский

Citations

214

Ultra-high color rendering warm-white light-emitting diodes based on an efficient green-emitting garnet phosphor for solid-state lighting DOI
Xiaoyong Huang, Jia Liang, Sami Rtimi

et al.

Chemical Engineering Journal, Journal Year: 2020, Volume and Issue: 405, P. 126950 - 126950

Published: Sept. 10, 2020

Language: Английский

Citations

210

A Novel Efficient Mn4+ Activated Ca14Al10Zn6O35 Phosphor: Application in Red-Emitting and White LEDs DOI
Wei Lü,

Wenzhen Lv,

Qi Zhao

et al.

Inorganic Chemistry, Journal Year: 2014, Volume and Issue: 53(22), P. 11985 - 11990

Published: Oct. 28, 2014

A new, highly efficient deep red-emitting phosphor Ca14Al10Zn6O35:Mn4+ was developed as a component of solid-state white light-emitting diodes (LEDs). The structural and optical characterization the is described. exhibits strong emission in range 650–700 nm when excited by 460 excitation, with quantum efficiency approaching 50%. Concentration dependence Mn4+ luminescence investigated. Attempts to understand thermal stability on basis quenching characteristics presented. results suggest that phosphors deriving from have potential application for LEDs. In addition, influence cation substitution intensity these elucidated.

Language: Английский

Citations

195

Crystal-Site Engineering Control for the Reduction of Eu3+ to Eu2+ in CaYAlO4: Structure Refinement and Tunable Emission Properties DOI
Yang Zhang, Xiaojing Li, Kai Li

et al.

ACS Applied Materials & Interfaces, Journal Year: 2015, Volume and Issue: 7(4), P. 2715 - 2725

Published: Jan. 15, 2015

In this article, Eu-activated CaYAlO4 aluminate phosphors were synthesized by a solid-state reaction. Under UV light excitation, characteristic red line emission of Eu3+ was detected in the range 570–650 nm. addition, we introduced crystal-site engineering approach into host through incorporation Si4+–Ca2+ to replace Al3+–Y3+, which would shrink AlO6 octahedrons, accompanied expansion CaO9 polyhedron, and then enable partial reduction Eu2+. The crystal structure underlying mechanism have been clarified on basis Rietveld refinement analysis. PL spectra Ca0.99+xY1–xAl1–xSixO4:Eu0.01 (x = 0–0.30) exhibit both green Eu2+ (4f65d1–4f7, broadband around 503 nm) red-orange (5D0–7F1,2, 593 624 under excitation with quantum yield 38.5%. CIE coordinates are regularly shifted from (0.482, 0.341) (0.223, 0.457) increasing x, expand application Eu. Furthermore, investigation reveals correlations property luminescent materials, shed development novel suitable for lighting display applications.

Language: Английский

Citations

189