Room-temperature synthesis, controllable morphology and optical characteristics of narrow-band red phosphor K2LiGaF6:Mn4+

CrystEngComm ◽  
2018 ◽  
Vol 20 (15) ◽  
pp. 2183-2192 ◽  
Author(s):  
Haiming Cheng ◽  
Yan Song ◽  
Feng Hong ◽  
Guixia Liu ◽  
Dan Li ◽  
...  

The white light-emitting diodes fabricated by mixing GaN chips with yellow phosphor (Y3Al5O12:Ce3+) and red phosphors (K2LiGaF6:Mn4+) exhibit good performance with lower color temperature and higher color rendering index.

Nanoscale ◽  
2021 ◽  
Author(s):  
Dongdong Yan ◽  
Qionghua Mo ◽  
Shuangyi Zhao ◽  
Wensi Cai ◽  
Zhigang Zang

With a high photoluminescence quantum yield (PLQY) being able to exceed 90% for those prepared by hot injection method, CsPbBr3 quantum dots (QDs) have attracted intensive attentions for white light-emitting...


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Chin-Chuan Huang ◽  
Tsung-Han Weng ◽  
Chun-Liang Lin ◽  
Yan-Kuin Su

White-light-emitting diodes (WLED) based on yttrium aluminum garnet (YAG) phosphors sintered with glass (PiG) and with silicone (PiS) are compared in terms of their light properties, temperature properties and reliability.The complete YAG phosphor was doped with an encapsulant traditional WLED (PiS WLED), and the WLED was covered with PiG (PiG WLED). PiG was made by sintering glass powder and YAG phosphor at the ratio of 87:13 (%), and the correlated color temperature (CCT) was 5564 K. The CCT of the PiG WLED with the YAG doping concentration of 8.5 wt.% approximated 5649 K. The initial light output of the PiG WLED was 6.4% lower than that of the PiS WLED. Under 1008 h and 350 mA aging, PiG WLED and PiS WLED’ light output, CCT and color rendering index variation rates were all within 1%. In the saturated vapor-pressure test, no sample exhibited red ink infiltration, light nor peeling between the encapsulant and the lead-frame. Compared with that of the PiS WLED, the junction temperature of the PiG WLED reduced from 88.4 °C to 81.3 °C. Thermal resistance dropped from 37.4 °C/W to 35.6 °C/W. The PiG WLED presented a better CIE (Commission Internationale de l’Eclairage) 1931 chromaticity coordinate (x,y) concentration and thermal properties than the PiS WLED.


Author(s):  
Bin Xie ◽  
Haochen Liu ◽  
Xiao Wei Sun ◽  
Xingjian Yu ◽  
Kai Wang ◽  
...  

White light-emitting diodes (WLEDs) composed of blue LED chip, yellow phosphor, and red quantum dots (QDs) are considered as a potential alternative for next-generation artificial light source with their high luminous efficiency (LE) and color-rendering index (CRI). While, QDs’ poor temperature stability and the incompatibility of QDs/silicone severely hinder the wide utilization of QDs-WLEDs. To relieve this, here we proposed a separated QSNs/phosphor structure, which composed of a QSNs-on-chip layer with a yellow phosphor layer above. A silica shell was coated onto the QDs surface to solve the compatibility problem between QDs and silicone. With CRI > 92 and R9 > 90, the newly proposed QDs@silica nanoparticles (QSNs) based WLEDs present 16.7 % higher LE and lower QDs working temperature over conventional mixed type WLEDs. The reduction of QDs’ temperature can reach 11.5 °C, 21.3 °C and 30.3 °C at driving current of 80 mA, 200 mA and 300 mA, respectively.


2018 ◽  
Vol 6 (11) ◽  
pp. 2741-2746 ◽  
Author(s):  
Ziyang Hou ◽  
Xueyuan Tang ◽  
Xuefang Luo ◽  
Tianliang Zhou ◽  
Lin Zhang ◽  
...  

A green synthetic route to the highly efficient K2SiF6:Mn4+narrow-band red phosphor for warm white light-emitting diodes.


2019 ◽  
Vol 48 (4) ◽  
pp. 1376-1385 ◽  
Author(s):  
Feng Hong ◽  
Haiming Cheng ◽  
Chao Song ◽  
Guixia Liu ◽  
Wensheng Yu ◽  
...  

Red phosphors (NH4)2NaInF6:Mn4+ with controllable morphology were synthesized via different synthetic methods, which can be fabricated for warm white LEDs.


2014 ◽  
Vol 07 (03) ◽  
pp. 1450033 ◽  
Author(s):  
Qingbo Liu ◽  
Yufeng Liu ◽  
Fu Yang ◽  
Bing Han ◽  
Hao Feng ◽  
...  

A novel orange-red phosphor Ca 3 B 2 O 6: Sm 3+, A+( A = Li , Na , K ) has been synthesized by solid-state reaction at 950°C. The phase purity and photoluminescence (PL) behavior of the phosphor are studied in detail using the powder X-ray diffraction (XRD) technique and PL measurements. Ca 3 B 2 O 6: Sm 3+ phosphor can be efficiently excited by near ultraviolet (n-UV) and blue light, and the emission spectrum consists of four emission peaks at 563, 599, 646 and 709 nm, generating bright orange-red light. When a cation A+ is introduced into Ca 3 B 2 O 6: Sm 3+ as charge compensator, the emission intensity of Ca 3 B 2 O 6: Sm 3+ is evidently enhanced, but the PL spectral profile is unchanged. The integral intensity of the emission spectrum of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 excited at 401 nm is about 1.2 times than that of Y 2 O 2 S : Eu 3+ commercial red phosphor. The CIE chromaticity coordinates of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 phosphor were (0.608, 0.365), which are close to that of the commercial red phosphors Y 2 O 3: Eu 3+ (0.655, 0.345), Y 2 O 2 S : Eu 3+ (0.622, 0.351) and Sr 2 Si 5 N 8: Eu 2+ (0.620, 0.370).


2015 ◽  
Vol 3 (9) ◽  
pp. 1935-1941 ◽  
Author(s):  
Lifen Lv ◽  
Zhen Chen ◽  
Guokui Liu ◽  
Shaoming Huang ◽  
Yuexiao Pan

The formation mechanism for red phosphors K2TiF6:Mn4+synthesized at room temperature has been discussed. The luminescence intensity has been improved by optimizing the synthetic process. Encapsulation of the red phosphor K2TiF6:Mn4+with YAG:Ce on a GaN layer produces “warm” white LEDs with color rendering 86 at 3251 K.


2018 ◽  
Vol 58 (1) ◽  
pp. 456-461 ◽  
Author(s):  
Zhengliang Wang ◽  
Zhiyu Yang ◽  
Zhaofeng Yang ◽  
Qianwen Wei ◽  
Qiang Zhou ◽  
...  

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