Molecular engineering of two-dimensional hybrid perovskites with broadband emission for white light-emitting diodes

2018 ◽  
Vol 6 (38) ◽  
pp. 10301-10307 ◽  
Author(s):  
Hongwei Hu ◽  
Samuel A. Morris ◽  
Xianfeng Qiao ◽  
Daming Zhao ◽  
Teddy Salim ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Emission ◽  
Molecular Engineering ◽  
Two Dimensional ◽  
Light Emitting ◽  
Broadband Emission ◽  
White Light Emitting Diodes

Two-dimensional (2D) hybrid perovskites exhibiting broadband light emission are attractive as down-converting phosphors in white light-emitting diodes (WLEDs).

The self-reduction synthesis and luminescent properties of Eu2+-Eu3+ activated BaZr0.2Si2O5.4 phosphors with white light emission for white light-emitting diodes

2018 ◽  
Vol 32 (04) ◽  
pp. 1850047 ◽  
Author(s):  
Jianlin Zhong ◽  
Lixin Yu ◽  
Songchu Li ◽  
Xiaoqin Man ◽  
Wei Sun
Keyword(s):  
White Light ◽  
Light Emission ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
White Light Emission ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Broadband Emission ◽  
White Light Emitting Diodes

The BaZr[Formula: see text]Si2O[Formula: see text]: Eu[Formula: see text]/Eu[Formula: see text] phosphors were prepared with different concentrations of Eu2O3 by a self-reduction method under air condition. The X-ray diffraction and the photoluminescence properties of the prepared samples were analyzed. The emission spectra consisting of a broadband emission from the 4f[Formula: see text]5d transitions of Eu[Formula: see text] and sharp emissions from 5D0-7F[Formula: see text] (J = 0, 1, 2, 3, 4) transitions of Eu[Formula: see text] are observed. The different luminescent colors can be obtained and modulated by doping different concentrations of Eu2O3 and the white light emission can be observed as the concentration of europium is 6%.

Improved Yellow Light Emission in the Achievement of Dichromatic White Light Emitting Diodes

2013 ◽  
Vol 1538 ◽  
pp. 371-375
Author(s):  
Zhao Si ◽  
Tongbo Wei ◽  
Jun Ma ◽  
Ning Zhang ◽  
Zhe Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Light Emission ◽  
Dual Wavelength ◽  
Emission Wavelength ◽  
White Led ◽  
Yellow Light ◽  
Light Emitting ◽  
White Light Emitting Diodes

ABSTRACTA study about the achievement of dichromatic white light-emitting diodes (LEDs) was performed. A series of dual wavelength LEDs with different last quantum-well (LQW) structure were fabricated. The bottom seven blue light QWs (close to n-GaN layer) of the four samples were the same. The LQW of sample A was 3 nm, and that of sample B, C and D were 6 nm, a special high In content ultra-thin layer was inserted in the middle of the LQW of sample C and on top of that of sample D. XRD results showed In concentration fluctuation and good interface quality of the four samples. PL measurements showed dual wavelength emitting, the blue light peak position of the four samples were almost the same, sample A with a narrower LQW showed an emission wavelength much shorter than that of sample B, C, D. EL measurement was done at an injection current of 100 mA. Sample A only showed LQW emission due to holes distribution. Because of wider LQW, the emission wavelength of sample B, C and D was longer and peak intensity was weaker. Sample D with insert layer on top of LQW showed strongest yellow light emission with a blue peak. As the injection current increased, sample A showed highest output light power due to narrower LQW. Of the other three samples with wider LQW, sample D showed highest output power. Effective yellow light emission has always been an obstacle to the achievement of dichromatic white LED. Sample D with insert layer close to p-GaN can confine the hole distribution more effectively hence the recombination of holes and electrons was enhanced, the yellow light emission was improved and dichromatic white LED was achieved.

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