Red to white polymer light-emitting diode (PLED) based on Eu3+–Zn2+–Gd3+-containing metallopolymer

2017 ◽  
Vol 5 (19) ◽  
pp. 4780-4787 ◽  
Author(s):  
Lin Liu ◽  
Hongyan Li ◽  
Peiyang Su ◽  
Zhao Zhang ◽  
Guorui Fu ◽  
...  

With color-tunable Eu3+–Zn2+–Gd3+-containing metallopolymer Poly(2-co-MMA-co-8) as the emitting layer, bright color-purity red-light PLED to first-example Ln3+-containing-metallopolymer-based WPLED were realized.

2001 ◽  
Vol 665 ◽  
Author(s):  
Serge Beaupré ◽  
Mario Leclerc ◽  
Isabelle Lévesque ◽  
Marie D'Iorio

ABSTRACTIn order to obtain efficient blue, green and red light-emitters as active layers in polymer light-emitting diode (PLEDs), we report herein the design, the synthesis, and the characterization of new polyesters and copolymers derived from fluorene. We will focus on a new approach to obtain a stable, high luminance blue emitter via polyesters derived from fluorene. The versatile synthetic approach allows the easy design of a whole class of new and tunable electroactive and photoactive aromatic polyesters. Poly(1,6-hexane- 9,9′,9′,9′′,9′′-hexahexyl-7,2′;7′,2′′-terfluorene-2,7′′-dicarboxylate) (PTFHHC6) and Poly(1,6-hexane-2,7-Bis(1,1′-biphenylen-4-yl-4′-dicarboxylate)-9,9-dioctylfluorene) (PE-BP-DOF-BP) exhibit strong emission in the blue range, both in solution and in the solid state. Moreover, these polyesters present some advantages over other polyfluorene derivatives. For example, their solid-state fluorescence spectrum does not show the formation of any excimer and does not vary upon thermal treatment. We will also present copolymers derived from fluorene which emit green light and a new approach to obtain red polymer light-emitting-diode will also be shown. Optical properties such as light absorption, light emission and quantum yield of fluorescence in solution as well as electrical properties such as cyclic voltammogram and conductivity in-situ are reported. Finally, some of the polymers presented have been tested in PLEDs devices and the preliminary results seem promising for the development of multicoloured displays made from the same class of polyfluorene derivatives.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5317
Author(s):  
Jingshan Hou ◽  
Wenxiang Yin ◽  
Langping Dong ◽  
Yang Li ◽  
Yufeng Liu ◽  
...  

In this work, a novel red-emitting oxyfluoride phosphor Na2NbOF5:Mn4+ with an ultra-intense zero-phonon line (ZPL) was successfully synthesized by hydrothermal method. The phase composition and luminescent properties of Na2NbOF5:Mn4+ were studied in detail. The photoluminescence excitation spectrum contains two intense excitation bands centered at 369 and 470 nm, which match well with commercial UV and blue light-emitting diode (LED) chips. When excited by 470 nm blue light, Na2NbOF5:Mn4+ exhibits red light emission dominated by ZPL. Notably, the color purity of the Na2NbOF5:Mn4+ red phosphor can reach 99.9%. Meanwhile, the Na2NbOF5:Mn4+ phosphor has a shorter fluorescence decay time than commercial K2SiF6:Mn4+, which is conducive to fast switching of images in display applications. Profiting from the intense ZPL, white light-emitting diode (WLED) with high color rendering index of Ra = 86.2 and low correlated color temperature of Tc = 3133 K is realized using yellow YAG:Ce3+ and red Na2NbOF5:Mn4+ phosphor. The WLED fabricated using CsPbBr3 quantum dots (QDs) and red Na2NbOF5:Mn4+ phosphor shows a wide color gamut of 127.56% NTSC (National Television Standard Committee). The results show that red-emitting Na2NbOF5:Mn4+ phosphor has potential application prospects in WLED lighting and display backlight.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.


2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).


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