High color rendering index single phase white light emitting phosphors based on Tb3+/Sm3+ co-doped CePO4 nanocrystals: the role of Tb3+ as a bridge between Ce3+ and Sm3+

2019 ◽  
Vol 43 (44) ◽  
pp. 17367-17382 ◽  
Author(s):  
Sisira S. ◽  
Linju Ann Jacob ◽  
Kamal P. Mani ◽  
Biju P. R. ◽  
N. V. Unnikrishnan ◽  
...  
Keyword(s):  
White Light ◽  
Single Phase ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Color Rendering Index ◽  
Cie Chromaticity ◽  
Color Rendering

Single phase white light emitting CePO4 nanocrystals doped with Tb3+ and Sm3+ were synthesized. The quality of white light is characterized by CIE chromaticity coordinates, color temperature, color rendering index and quantum yield.

scholarly journals Chromaticity Study of Curcumin Dye Extracted from Curcuma longa L. Using for UV Light down Conversion for White Light Emitting Diode

2019 ◽  
Vol 290 ◽  
pp. 183-189
Author(s):  
Mahmood Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Major Factors ◽  
Color Rendering ◽  
Down Conversion

In thus study, Turmeric phosphor dye was extracted from Curcuma Longa L. via a simple technique using silica gel. The phosphor was used for light down-conversion of UV light for the manufacture white light emitting diode (WLED). The UV-LED was analyzed over 395nm wavelengths. The characteristics of the white light chromaticity were controlled by tuning the current and phosphor concentration. An optimum color rendering index (CRI) value of 63.4 was obtained. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for various currents and phosphor concentrations. The white phosphor exhibited CIE value of 0.355,0.338 and CCT of 4567 K. The concentration of phosphor and amount of applied current were confirmed to be major factors that control the intensity of white light emitted from the sample, where CIE and CRI of the emitted light steadily increased with the concentration of phosphor and current. Thus, phosphor concentration has a critical effect on conversion efficiency. Key words: Turmeric, phosphor, WLED, curcumin

Crystal structure and photoluminescence tuning of novel single-phase Ca8ZnLu(PO4)7:Eu2+,Mn2+ phosphors for near-UV converted white light-emitting diodes

2019 ◽  
Vol 7 (27) ◽  
pp. 8374-8382 ◽  
Author(s):  
Jing Yan ◽  
Ziwang Zhang ◽  
Dawei Wen ◽  
Jianbang Zhou ◽  
Yiqin Xu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
White Light ◽  
Single Phase ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Tunable ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

A single phase color-tunable white light emitting Ca8ZnLu(PO4)7:Eu2+,Mn2+ phosphor with high color rendering index has been rationally designed via combination of cyan and red emissions.

A semi-conductive organic–inorganic hybrid emits pure white light with an ultrahigh color rendering index

2017 ◽  
Vol 5 (19) ◽  
pp. 4731-4735 ◽  
Author(s):  
Sasa Wang ◽  
Lina Li ◽  
Zhihua Sun ◽  
Chengmin Ji ◽  
Sijie Liu ◽  
...  
Keyword(s):  
White Light ◽  
Single Component ◽  
Inorganic Hybrid ◽  
Chromaticity Coordinates ◽  
Color Rendering Index ◽  
Cie Chromaticity ◽  
Color Rendering ◽  
Pure White

A single-component semiconductor emits pure white light with CIE chromaticity coordinates of (0.33, 0.33) and an ultrahigh color rendering index of 92.5.

Mn2+and Mn4+red phosphors: synthesis, luminescence and applications in WLEDs. A review

2018 ◽  
Vol 6 (11) ◽  
pp. 2652-2671 ◽  
Author(s):  
Qiang Zhou ◽  
Leonid Dolgov ◽  
Alok M. Srivastava ◽  
Lei Zhou ◽  
Zhengliang Wang ◽  
...  
Keyword(s):  
Transition Metal ◽  
White Light ◽  
Light Emitting Diodes ◽  
Color Temperature ◽  
Luminescent Materials ◽  
Light Emitting ◽  
Red Phosphors ◽  
Important Family ◽  
Color Rendering Index ◽  
Color Rendering

Transition-metal activated phosphors are an important family of luminescent materials that can produce white light with an outstanding color rendering index and correlated color temperature for use in light-emitting diodes.

Correlated color temperature tunability and energy transfer phenomenon in the NaBaBO3:Dy3+/Eu3+ phosphor for white light application

2015 ◽  
Vol 08 (06) ◽  
pp. 1550077 ◽  
Author(s):  
Jianghui Zheng ◽  
Qijin Cheng ◽  
Cheng Zheng ◽  
Guo Chen ◽  
Feng Shi ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Single Phase ◽  
Color Temperature ◽  
Light Emitting ◽  
Transfer Phenomenon ◽  
Near Ultraviolet ◽  
Cie Chromaticity ◽  
Co Doped ◽  
The Eu

NaBa 0.97-x BO 3 0.03 Dy 3+, x Eu 3+(0 ≤ x ≤ 0.09) single-phase white phosphors with tunable correlated color temperature (CCT) were synthesized using a conventional solid state reaction method. The phase structure and luminescence properties of the as-prepared samples were investigated. The Dy 3+, Eu 3+ doped and Dy 3+/ Eu 3+ co-doped NaBaBO 3 phosphors excited by 361 nm show two blue and yellow emissions corresponding to the 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions of Dy 3+ ions and two red emissions due to the 5 D 0 → 4 F J (J = 1, 2) transitions of Eu 3+ ions. Under 361-nm light excitation, the NaBa 0.97-x BO 3 0.03 Dy 3+, x Eu 3+(0 ≤ x ≤ 0.09) phosphors feature a white light emitting property. Through the Commission Internationale de L'Eclairage (CIE) chromaticity analysis and CCT calculation, the CIE chromaticity coordinates of the emission light are all located in the white region and can be tuned from bluish white light to reddish white light when the Eu 3+ concentration increases, and the CCT values of the obtained samples can vary from 5514.31 K to 8269.42 K. Furthermore, the energy transfer phenomenon from Dy 3+ ions to Eu 3+ ions in Dy 3+/ Eu 3+ co-doped samples was also investigated. The results indicated that, through tuning the Eu 3+ concentration of the NaBaBO 3: Dy 3+/ Eu 3+ phosphors, the NaBaBO 3-based phosphor can act as a potential single-phase white emitting phosphor for the application in the near-ultraviolet (NUV) white light emitting diodes.

A lead-free semiconducting hybrid with ultra-high color rendering index white-light emission

2018 ◽  
Vol 6 (11) ◽  
pp. 2801-2805 ◽  
Author(s):  
Asma Khan ◽  
Aurang Zeb ◽  
Lina Li ◽  
Weichuan Zhang ◽  
Zhihua Sun ◽  
...  
Keyword(s):  
White Light ◽  
Light Emission ◽  
White Light Emission ◽  
Lead Free ◽  
One Dimensional ◽  
Chromaticity Coordinates ◽  
Color Rendering Index ◽  
Cie Chromaticity ◽  
Color Rendering

We present a one-dimensional lead-free semiconducting hybrid exhibiting white-light emission with an ultra-high CRI of 96.29 and CIE chromaticity coordinates of (0.32, 0.33).

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