Thermally Stable Encapsulation Material Based on Green and Red Lanthanide Phosphor for White Light Emitting Diodes

2015 ◽  
Vol 815 ◽  
pp. 182-187
Author(s):  
Wedianti Shualdi ◽  
Nik Mohd Azmi ◽  
Nurul Huda Yusoff ◽  
Nor Adhila Muhammad ◽  
Khairuldin Mohd Isha
Keyword(s):  
White Light ◽  
Sol Gel ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Light Emitting ◽  
Colour Temperature ◽  
Uv Led ◽  
Lanthanides Complexes ◽  
The Stability ◽  
White Light Emitting Diodes

This study reported thermal stability of hybrid sol-gel encapsulation materials doped with lanthanides complexes for generating white light. Red and green lanthanide phosphor, Eu (tta)3phen and Tb (4DBBA)3TPPO were incorporated into VTES:TEOS hybrid sol-gel and dispensed into 360 nm to 390 nm UV LED packages. Thermal properties of developed encapsulation material were analysed by TGA. A thermal aging test up to 96 hours was done to check the stability of developed encapsulation material towards UV LED junction temperature of 120°C and the luminescence properties changes was observed using photoluminescence measurement. To check the encapsulation material stability on forward voltage, the operation voltage has been increased from 3.0V to 4.0V. The photometric measurement were recorded using integrating sphere for the properties of Colour Rendering Index (CRI), colour temperature and Commission Internationale de L’Eclairge (CIE) colour coordinates. Based on the results, developed encapsulation material produced white colour with CIE colour coordinate of (0.32, 0.35), CRI up to 75 and colour temperature around 6000K.

scholarly journals Broad near-ultraviolet and blue excitation band induced dazzling red emissions in Eu3+-activated Gd2MoO6 phosphors for white light-emitting diodes

RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3170-3178 ◽  
Author(s):  
Peng Du ◽  
Yue Guo ◽  
Soo Hyun Lee ◽  
Jae Su Yu
Keyword(s):  
Citric Acid ◽  
White Light ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Excitation Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Blue Excitation ◽  
White Light Emitting Diodes

A series of Eu3+-activated Gd2MoO6 phosphors were synthesized via a citric acid-assisted sol–gel route.

ACCURATE MEASUREMENT OF ULTRAVIOLET LIGHT-EMITTING DIODES

2021 ◽  
Author(s):  
C. Yuqin Zong ◽  
Cameron Miller
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Luminous Flux ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Light Emitting ◽  
Type D ◽  
Uv Led ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes

We have developed a new calibration capability for 200 nm to 400 nm ultraviolet light-emitting diodes (UV LEDs) using a Type D gonio-spectroradiometer. The recently-introduced mean differential continuous pulse (M-DCP) method is used to overcome the measurement difficulty associated with the initial forward voltage, VF, anomaly of a UV LED, which makes it impossible to use VF to infer junction temperature, TJ, during pulsed operation. The new measurement facility was validated indirectly by comparing the measured total luminous flux of a white LED with that measured using the NIST’s 2.5 m absolute integrating sphere. The expanded calibration uncertainty for the total radiant flux is approximately 2 % to 3 % (k = 2) depending the wavelength of the UV LED.

A promising red-emitting phosphor for white light emitting diodes prepared by sol–gel method

2008 ◽  
Vol 133 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Chongfeng Guo ◽  
Wei Zhang ◽  
Lin Luan ◽  
Tao Chen ◽  
Hong Cheng ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Light Emitting ◽  
Gel Method ◽  
Sol Gel Method ◽  
White Light Emitting Diodes ◽  
Red Emitting Phosphor

A potential green-emitting phosphor Ca8Mg(SiO4)4Cl2:Eu2+ for white light emitting diodes prepared by sol–gel method

2011 ◽  
Vol 257 (21) ◽  
pp. 8836-8839 ◽  
Author(s):  
Chongfeng Guo ◽  
Ming Li ◽  
Yan Xu ◽  
Ting Li ◽  
Zhaoyu Ren ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Light Emitting ◽  
Gel Method ◽  
Sol Gel Method ◽  
White Light Emitting Diodes

Luminescence properties of single-phase color-tunable Li4SrCa(Si2O4N8/3):Eu2+ phosphor for white light-emitting diodes

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 38731-38740 ◽  
Author(s):  
Chenxia Li ◽  
Jian Dai ◽  
Hua Yu ◽  
Degang Deng ◽  
Jun Huang ◽  
...  
Keyword(s):  
White Light ◽  
Single Phase ◽  
Light Emitting Diodes ◽  
Color Temperature ◽  
White Led ◽  
Light Emitting ◽  
Color Coordinates ◽  
Uv Led ◽  
Color Tunable ◽  
White Light Emitting Diodes

A white LED consisting of a LSCSN:0.03Eu2+ phosphor and a 375 nm UV LED chip had CIE color coordinates of (0.3568, 0.3111) and achieved a Ra of 82.5 around the correlated color temperature of 3318 K.

scholarly journals Sr2−xBaxTiO4:Eu3+, Gd3+: A Novel Blue Converting Yellow-Emitting Phosphor for White Light-Emitting Diodes

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Limin Dong ◽  
Jiatong Zhao ◽  
Qin Li ◽  
Zhidong Han
Keyword(s):  
Blue Light ◽  
White Light ◽  
Single Phase ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Sol Gel ◽  
Excitation Wavelength ◽  
Light Emitting ◽  
Gel Method ◽  
White Light Emitting Diodes

A highly intense yellow-emitting phosphorSr2-xBaxTiO4:Eu3+,Gd3+peaking at 593–611 nm was synthesized by the sol-gel method. XRD and SEM show that the samples are single phase and have irregular shape. The excitation wavelength matches well with that of the emission of the blue-light-emitting diode. The emission peaks at 593 and 611 nm are attributed to the transitions from the5D0-7F1and5D0-7F2ofEu3+ions, respectively.Gd3+was used as sensitizer, aiming at increasing the luminous intensity. A certain amount ofSr2+andBa2+is contributed to the intensity of light emission.

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