An optimisation toolbox for multi-colour LED lighting

2016 ◽  
Vol 50 (3) ◽  
pp. 467-481 ◽  
Author(s):  
S Afshari ◽  
L Moynihan ◽  
S Mishra
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Optimal Choice ◽  
Light Emitting ◽  
Conference Room ◽  
Channel Choice ◽  
White Light Generation ◽  
Manufacturing Applications ◽  
The Individual ◽  
Mixing Problem

This paper introduces a software toolbox designed for the optimisation of white light generation using multiple light-emitting diode (LED) channels. The toolbox solves two separate types of multi-colour optimisation problems. These are the multi-channel mixing and the channel choice problems. In the multi-channel mixing problem, it is assumed that the available LEDs are pre-determined and fixed. The toolbox obtains the individual channel intensities that solve a constrained optimisation problem based on the mixed output light. It provides the user with the flexibility to choose an arbitrary formulation for the optimisation problem as well as various mathematical metrics to represent the different properties of the output light including colour rendering, power efficiency and colour accuracy. For the channel choice problem, the toolbox solves for the number and type of used LED channels as well as the intensity of individual channels to assist in optimal choice of deployed channels for luminaire manufacturing applications. This paper describes the graphical user interface and the back-end formulation of the optimisation problem and presents experimental results obtained by utilising the toolbox in a full-size conference room with 5-channel LED luminaires.

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 A hybrid inorganic–organic light-emitting diode using Ti-doped ZrO2 as an electron-injection layer

RSC Advances ◽  
2018 ◽  
Vol 8 (15) ◽  
pp. 8402-8411 ◽  
Author(s):  
Jayaraman Jayabharathi ◽  
Sekar Panimozhi ◽  
Venugopal Thanikachalam ◽  
Annadurai Prabhakaran ◽  
Palanivel Jeeva
Keyword(s):  
Current Efficiency ◽  
Power Efficiency ◽  
Light Emitting Diode ◽  
Electron Injection ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Electron Injection Layer ◽  
Organic Light

Ti-doped ZrO2 facilitates electron injection effectively, leading to enhanced current efficiency of 2.84 cd A−1 and power efficiency of 1.32 lm W−1

High Brightness White Organic Light Emitting Devices Employing Phosphorescent Iridium Complex as RGB Dopants

2007 ◽  
Vol 364-366 ◽  
pp. 1072-1076
Author(s):  
Rui Li Song ◽  
Yu Duan
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Iridium Complex ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Color Mixing ◽  
Coordinate Changes ◽  
Cie Chromaticity

An efficient phosphorescent white organic light-emitting diode (WOLED) was realized by using a bright blue-emitting layer, iridium (III) bis [(4, 6-di-fluoropheny)-pyridinato-N, C2’] picolinate doped 4.4’-bis (9-carbazolyl)-2, 2’-dimethyl-biphenyl, together with tris (2- Phenylpyridine) iridium and bis (1-phenyl-isoquinoline) acetylacetonate iridium (III) were codoped into 4,4’-N,N’-dicarbazole-biphenyl layer to provide blue, green, and red emission for color mixing. The device emission color was controlled by varying dopant concentrations and the thickness of blue and green-red layers as well as tuning the thickness of exciton-blocking layer. The maximum luminance and power efficiency of the WOLED were 37100cd/m2 at 17 V and 7.37lm/W at 5V, respectively. The Commission Internationale de 1’Eclairage (CIE) chromaticity coordinate changes from (0.41, 0.42) to (0.37, 0.39) when the luminance rangeed from 1000cd/m2 to 30000cd/m2.

Modeling and Analysis of Organic Light Emitting Diode with Thin Film Anti-Reflective Coatings

2020 ◽  
Vol 15 (4) ◽  
pp. 425-431
Author(s):  
B. M. Chaya ◽  
Prasant Kumar Pattnaik ◽  
K. Narayan
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Fdtd Method ◽  
Light Output ◽  
Single Layer ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Reflective Coating ◽  
Organic Light ◽  
Reflective Coatings

The effects of anti-reflective coatings (ARC) on organic light emitting diode (OLED) optical characteristics are reported in this paper. The light output produced from the OLED is not 100%. But the emitted light is trapped due to various Modes. The losses at the glass air substrate interfaces of an OLED are addressed in this work. The Anti-Reflective coatings increase the light output by reducing OLED reflections at the interface between glass and air. The Finite Difference Time Domain (FDTD) method and the Fresnel theory have been used to design the device and study the effects on OLED of the Single Layer Anti-Reflective Coating (SLAR) and Double Layer Anti-Reflective Coating (DLAR). The thicknesses and refractive indices of the layers of the anti-reflective coatings were optimized. We also compared the light out coupling power efficiency of the SLAR coated OLED with that of an OLED with a DLAR coating and also with Conventional OLED. The results show that the enhancement in light output efficiency of the DLAR coated OLED was slightly higher than that of the SLAR coated OLED.

UV_Blue Light Conversion Using Dyes Polymeric Materials

2020 ◽  
Vol 301 ◽  
pp. 52-59
Author(s):  
Alaa Falih Ismael
Keyword(s):  
Blue Light ◽  
White Light ◽  
Light Emitting Diode ◽  
Polymeric Materials ◽  
Environmental Friendliness ◽  
Light Emitting ◽  
Laboratory Technique ◽  
Silicone Sealant ◽  
White Light Generation ◽  
New Generation

White light-emitting diode (LED) is used in a new generation of solid-state lighting due to its advantages in energy saving and environmental friendliness. Based on this assumption, Emphasis was put on trying to establish a laboratory technique to convert UV-blue light into white light by using polymeric materials. In this work, an laboratory technique to convert UV-blue light into white light by using polymeric materials, consisting of red (R), green (G) and blue (B) for a white light generation. The project employed the use Colouring polymorph plastic as an active materials mixed with Silicone Sealant in different ratio and pumping by UV-Blue light. Colour rendering index (CRI) and correlated colour temperature (CCT) as main measurement parameters to evaluate the performance of the white light. The best white light appearance an indicated by photo and colour meter were achieved by mixing red (R), 0.05gm and green (G), 0.1gm the optimum results were CCT =3606k, CRI =70.3, x=0.3661, y=0.2925, and by mixing red (R), 0.005gm and green (G), 0.005gm the results were CCT=4891 k, CRI =63.8 and x=0.3359, y=0.2405.

Improved power efficiency in phosphorus doped n-a-SiNxOy/p-Si heterojunction light emitting diode

2017 ◽  
Vol 110 (8) ◽  
pp. 081109 ◽  
Author(s):  
Zewen Lin ◽  
Kunji Chen ◽  
Pengzhan Zhang ◽  
Jun Xu ◽  
Wei Li ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Phosphorus Doped

scholarly journals Hermetic Seal of Organic Light Emitting Diode with Glass Frit

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 76
Author(s):  
Chien-Liang Chiu ◽  
Meng-Syun Lin ◽  
Yi-Chen Wu
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Glass Frit ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Hermetic Sealing ◽  
Hermetic Seal ◽  
20 Nm ◽  
532 Nm ◽  
A Current

The components of OLED encapsulation with hermetic sealing and a 1026-day lifetime were measured by PXI-1033. The optimal characteristics were obtained when the thickness of the TPBi layer was 20 nm. This OLED obtained a maximum luminance (Lmax) of 25,849 cd/m2 at a current density of 1242 mA/cm2, an external quantum efficiency (EQE) of 2.28%, a current efficiency (CE) of 7.20 cd/A, and a power efficiency (PE) of 5.28 lm/W. The efficiency was enhanced by Lmax 17.2%/EQE 0.89%/CE 42.1%/PE 41.9%. The CIE coordinates of 0.32, 0.54 were all green OLED elements with wavelengths of 532 nm. The shear strain and leakage test gave results of 16 kgf and 8.92 × 10−9 mbar/s, respectively. The reliability test showed that the standard of MIL-STD-883 was obtained.

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