Improved Efficiency in Organic Light Emitting Device with a Excton Confining Structure

2013 ◽  
Vol 750-752 ◽  
pp. 1063-1067
Author(s):  
Hui Shan Yang ◽  
Li Shuang Wu ◽  
Yu Zhuo Pan
Keyword(s):  
Current Efficiency ◽  
White Light ◽  
Light Emission ◽  
Operating Voltage ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Organic Light ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
Two Peaks

A white organic light emitting device (WOLED) with excton confining structure is reported. The blue and red emitting layer consist of 1,4bis (2,2-diphenyl vinyl) benzene (DPVBi) and the bis (1-(phenyl) isoquinoline) iridium (III) acetylanetonate [Ir (piq)2(acac)] doped into 4,4(-N,N)-dicarbazole-biphenyl (CBP) host, respectively. The devices were made of ITO/ m-MTDATA (40 nm)/ NPB (10 nm) /DPVBi (8 nm)/ Bhen (xnm)/ CBP: Ir (piq)2(acac) 2% 5nm/ Alq (50 nm )/ LiF (1 nm)/Al (200 nm), by adding excton confining layer, with only a small increase in operating voltage. However, the efficiency of device increases. The electroluminescent (EL) spectra exhibit two peaks at 456 and 628 nm, resulting in white light emission with the Commission Internationale dEclairage (CIE) chromaticity coordinates of (0.222, 0.2402) at 4V to (0.1924, 0.1986) at 13V whenxis 8, while the device shows the current efficiency of 4.79 cd/A at 6V, its maximum luminance is 14130 cd/m2at 13V, respectively.

White Organic Light-Emitting Devices Using the Blue and Green Fluorescent Emitting Layer Structure Incorporating with Red Phosphorescent Emitting Layer

2013 ◽  
Vol 753-755 ◽  
pp. 2521-2525
Author(s):  
Li Shuang Wu ◽  
Hui Shan Yang
Keyword(s):  
Light Emission ◽  
Layer Structure ◽  
Organic Light Emitting Diodes ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Chromaticity Coordinates ◽  
Green Fluorescent ◽  
Cie Chromaticity

Efficient white organic light-emitting diodes are fabricated with the blue and green fluorescent incorporating red phosphorescent emitting layer. The blue, green and red emitting layer consist of 1,4-bis (2,2-diphenyl vinyl) benzene (DPVBi), tris (8-hydroxyquinoline) aluminium (Alq) and the bis (1-(phenyl) isoquinoline) iridium (III) acetylanetonate [Ir (piq)2(acac)] doped into 4,4(-N,N)-dicarbazole-biphenyl (CBP) host, respectively. The devices were made of ITO/ m-MTDATA (40 nm)/ NPB (10 nm) /DPVBi (8 nm)/ CBP: Ir (piq)2(acac) x% 5nm/ Alq (50 nm )/ LiF (1 nm) / Al (200 nm). The electroluminescent (EL) spectra exhibit three peaks at 456, 520 and 620 nm, resulting in white light-emission with the Commission Internationale dEclairage (CIE) chromaticity coordinates of (0.37, 0.44) at 4V to (0.23, 0.30) at 13V when x is 4, while the device shows the current efficiency of 4.0 cd/A at 6V, and its maximum luminance is 21660 cd/m2 at 13V, respectively.

Optimization for white organic light-emitting diode based on DCJTB as color conversion layer

2018 ◽  
Vol 32 (27) ◽  
pp. 1850299
Author(s):  
Pei Wang ◽  
Zhen Wang ◽  
Ai Chen ◽  
Jia-Feng Xie ◽  
Xin Zheng
Keyword(s):  
Current Efficiency ◽  
Current Density ◽  
White Light ◽  
Power Efficiency ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
High Efficient ◽  
Color Conversion

In this paper, combining phosphorescence and fluorescence to form white light was realized based on DCJTB:PMMA/ITO/NPB/TCTA/FIrpic:TCTA/TPBi/Ir(ppy)3:TPBi/TPBi/Cs2CO3/Al. The effects of red fluorescence on this white light device was studied by adjusting the concentration of DCJTB. The study shows that the device with a DCJTB concentration of 0.7% in the color conversion layer (CCL) generates a peak current efficiency and power efficiency of 23.4 cd ⋅ A[Formula: see text] and 7.5 lm ⋅ W[Formula: see text], respectively. And it is closest to the equal-energy white point of (0.33, 0.33) which shows a CIE (Commission Internationale de L’Eclairage) coordinate of (0.35, 0.43) and a color rendering index (CRI) of 70 at current density of 10 mA ⋅ cm[Formula: see text]. In order to improve the efficiency, we design and fabricate both high efficient and pure white organic light-emitting diode (WOLED) by replacing the single blue emission layer (EML) with double EMLs of FIrpic:TCTA and FIrpic:TPBi. The further study shows that, when the layers of EML is three and the concentration of DCJTB at 0.7%, the device exhibits good performance specifically, at current density of 10 mA ⋅ cm[Formula: see text], the current efficiency of 28.2 cd ⋅ A[Formula: see text] (power efficiency of 10.3 lm ⋅ W[Formula: see text]), and the CIE coordinate of (0.33, 0.31) (CRI of 80.38).

scholarly journals Effects of Bi3+ Ion-Doped on the Microstructure and Photoluminescence of La0.97Pr0.03VO4 Phosphor

2021 ◽  
Vol 6 (3) ◽  
pp. 191-198
Author(s):  
Hao-Long Chen ◽  
Hung-Rung Shih ◽  
Sean Wu ◽  
Yee-Shin Chang
Keyword(s):  
White Light ◽  
Emission Intensity ◽  
Sol Gel ◽  
Blue Shift ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates ◽  
Ion Doping ◽  
Ion Contents ◽  
Cie Chromaticity

The objective of this paper is to enhance the emission intensity of La0.97Pr0.03VO4 single-phased white light emitting phosphor. The Bi3+ ion-doped La0.97Pr0.03VO4 single-phased white light emitting phosphors are synthesized using a sol-gel method. The structure and photoluminescence properties of (La0.97-yBiy)Pr0.03VO4 (y = 0-0.05) phosphor are also examined. The XRD results show that the structure of La0.97Pr0.03VO4 phosphors with different concentrations of Bi3+ ion doping keeps the monoclinic structure. The SEM results show that the phosphor particles become smoother when the Bi3+ ion is doped. The excitation band for La0.97Pr0.03VO4 phosphor exhibits a blue shift from 320 nm to 308 nm as the Bi3+ ion contents are increased. The maximum emission intensity is achieved for a Bi3+ ion content of 0.5 mol%, which is about 30% greater than that with no Bi3+ ion doped. The CIE chromaticity coordinates are all located in the near white light region for different Bi3+ ion-doped La0.97Pr0.03VO4 phosphors.

scholarly journals White light emission produced by CTMA-DNA nanolayers embedded with a mixture of organic light-emitting molecules

RSC Advances ◽  
2019 ◽  
Vol 9 (54) ◽  
pp. 31628-31635 ◽  
Author(s):  
Prathamesh Chopade ◽  
Sreekantha Reddy Dugasani ◽  
Sohee Jeon ◽  
Jun-Ho Jeong ◽  
Sung Ha Park
Keyword(s):  
White Light ◽  
Light Emission ◽  
White Light Emission ◽  
Light Emitting ◽  
Organic Light

White light emission produced by organic light-emitting molecule-embedded CTMA-DNA nanolayers was demonstrated.

Perovskite white light-emitting diodes with a perovskite emissive layer blended with rhodamine 6G

2020 ◽  
Vol 8 (37) ◽  
pp. 12951-12958 ◽  
Author(s):  
Che-Yu Chang ◽  
Wei-Li Hong ◽  
Pei-Hsuan Lo ◽  
Tzu-Hsiang Wen ◽  
Sheng-Fu Horng ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Rhodamine 6G ◽  
Light Emitting ◽  
Emissive Layer ◽  
Chromaticity Coordinates ◽  
Halide Perovskites ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

Perovskite white light-emitting diodes with only a single emissive layer of halide perovskites and rhodamine 6G were realized with the CIE chromaticity coordinates of (0.33, 0.40).

Efficiency Enhancement of Tandem Organic Light-Emitting Devices Fabricated Utilizing an Organic BEDT-TTF and HAT-CN Charge Generation Layer

2015 ◽  
Vol 15 (10) ◽  
pp. 8070-8074
Author(s):  
Dae Hun Kim ◽  
Tae Whan Kim
Keyword(s):  
Current Efficiency ◽  
Operating Voltage ◽  
Efficiency Enhancement ◽  
Charge Generation ◽  
Electrical And Optical Properties ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Highest Occupied Molecular Orbital ◽  
Organic Light Emitting Devices

The electrical and optical properties of tandem organic light-emitting devices (OLEDs) fabricated utilizing an organic bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) and 1,4,5,8,9,11- hexaazatriphenylenehexacarbonitrile (HAT-CN) charge generation layer (CGL) were investigated to enhance their efficiency. While the operating voltage of the tandem OLEDs with a BEDT-TTF and HAT-CN CGL at 50 mA/cm2 was 11.2 V lower than that of the tandem OLEDs without a CGL, the current efficiency of the tandem OLEDs with a BEDT-TTF and a HAT-CN CGL at 50 mA/cm2 was 0.8 cd/A higher than that of the tandem OLEDs without a CGL. An increase in the current efficiency and a decrease in the operating voltage of the tandem OLEDs with a BEDT-TTF and an HAT-CN CGL were attributed to the enhancement of the electron injection due to its existence in the highest occupied molecular orbital level of the BEDT-TTF between the HAT-CN and the tris-(8- hydroxyquinoline)aluminum layer.

scholarly journals Organic Light Emitting Diodes for White Light Emission

10.5772/9892 ◽  
2010 ◽  
Author(s):  
Ritu Srivastava ◽  
M.N. Kamalasanan ◽  
Gayatri Chauhan ◽  
Arunandan Kumar ◽  
Priyanka Tyagi ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Emission ◽  
White Light Emission ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

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.

Improved Efficiency in Organic Light Emitting Device Based on 4,4-bis(2,2-diphenylvinyl)-1,1-biphenyl as Hole Blocking Layer

2014 ◽  
Vol 536-537 ◽  
pp. 1426-1430 ◽  
Author(s):  
Hui Shan Yang ◽  
Li Shuang Wu ◽  
Zhi Yue Huang
Keyword(s):  
Current Efficiency ◽  
Multilayer Structure ◽  
Blocking Layer ◽  
Maximum Luminance ◽  
Thickness Control ◽  
Light Emitting ◽  
Organic Light ◽  
Device Efficiency ◽  
Hole Blocking Layer ◽  
Ultrathin Layer

An organic light emitting device (OLED) with multilayer structure is reported. The devices were made of ITO/ m-MTDATA (45 nm)/ NPB (10 nm) / DCJTB (0.05 nm)/DPVBi (x nm)/ Alq:QAD 0.5% 20nm /Alq (50-x nm)/LiF(1nm)/Al, by doping combine with non-doping method. The ultrathin layer was introduced for the yellow emitting layer by using 4- (dicyanomethylene)-2-tert-butyl-6 (1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB). The ultrathin layer offered an attraction in that it allowed the easy handling process and accurate thickness control, it enabled high device efficiency with simple architecture.The device shows the current efficiency of 2.79 cd/A at 12V, its maximum luminance is 17450 cd/m2 at 14V, respectively.

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