Effects of Doping Concentration on the Performance of Blue Fluorescent OLEDs

2015 ◽  
Vol 778 ◽  
pp. 96-99
Author(s):  
Gang Zhang ◽  
Xi Yan Zhang
Keyword(s):  
Current Efficiency ◽  
Blue Light ◽  
Mass Fraction ◽  
Doping Concentration ◽  
Fluorescent Dyes ◽  
Fluorescent Dye ◽  
Driving Voltage ◽  
Maximum Luminance ◽  
Maximum Current ◽  
Efficient Roll

The OLEDs were fabricated with the structure of ITO/m-MTDATA(20nm)/NPB(10nm)/ DPVBi:BCzVBi(15 nm,x%)/TPBi(10 nm)/Alq3(20nm)/Cs2CO3：Ag2O(2nm,20%)/ Al (100 nm) by using the method of fluorescent dyes dopant. The effect of different DPVBi:BCzVBi doping concentration(x=5,8, 10 and 15) on the properties of blue light device was studied．Results show that when the mass fraction of fluorescent dye BCzVBi was 10%, performances of the device were the best. This device had a maximum current efficiency of 4.19 cd /A and maximum luminance of 14757 cd /m2at 17 V.When the driving voltage changed from 8 to 17 V, the efficiency of the devices had been rising. There are not the phenomenon of efficient roll-off.

Highly efficient orange-red electroluminescence of iridium complexes with good electron mobility

2017 ◽  
Vol 5 (32) ◽  
pp. 8150-8159 ◽  
Author(s):  
Hua-Bo Han ◽  
Rong-Zhen Cui ◽  
Yi-Ming Jing ◽  
Guang-Zhao Lu ◽  
You-Xuan Zheng ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Electron Mobility ◽  
Quantum Yields ◽  
Iridium Complexes ◽  
Maximum Luminance ◽  
High Quantum ◽  
Highly Efficient ◽  
Maximum Current ◽  
Low Efficiency

Two orange-red iridium complexes with high quantum yields and good electron mobility were applied in efficient OLEDs showing a maximum luminance of 129 466 cd m−2, a maximum current efficiency of 62.96 cd A−1 with low efficiency roll-off.

Chroma Stability of WOLED with High-Voltage

2018 ◽  
Vol 10 (3) ◽  
pp. 383-388
Author(s):  
Hongbo Liu ◽  
Lizhong Wang ◽  
Mingxing Song ◽  
Shumei Li
Keyword(s):  
Energy Transfer ◽  
Doping Concentration ◽  
Light Emission ◽  
Forward Bias ◽  
Blue Dye ◽  
Maximum Luminance ◽  
Forward Bias Voltage ◽  
Maximum Current ◽  
Dye Doping ◽  
Red Dye

Multilayer chroma stability of white OLEDs was realized with blue dye DPVBi and red dye DCJTB doped as luminescence layer. The blue dye doping concentration was kept at 6%, at the same time the red dye was reduced from 4%, 2%, 1% to 0.5%. The device color coordinates (CIE) were adjusted from (0.58, 0.42) to (0.31, 0.32), achieving the white light emission. A stable white emission for forward bias voltage changes from 6 to 17 V has been achieved. Its maximum luminance was 15030 cd/m2 at 17 V, and the maximum current efficiency was 4.65 cd/A at 9 V. We contributed the main reason of chroma stability to the complete energy transfer from CBP to DCJTB and the incomplete energy transfer between DPVBi and DCJTB by analyzing the spectrum and characteristic of the device so its performance was enhanced.

scholarly journals Improved Efficiency of Perovskite Light-Emitting Diodes Using a Three-Step Spin-Coated CH3NH3PbBr3 Emitter and a PEDOT:PSS/MoO3-Ammonia Composite Hole Transport Layer

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 459 ◽  
Author(s):  
Yuanming Zhou ◽  
Sijiong Mei ◽  
Dongwei Sun ◽  
Neng Liu ◽  
Wuxing Shi ◽  
...  
Keyword(s):  
Current Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Control Device ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Injection ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Maximum Current

High efficiency perovskite light-emitting diodes (PeLEDs) using PEDOT:PSS/MoO3-ammonia composite hole transport layers (HTLs) with different MoO3-ammonia ratios were prepared and characterized. For PeLEDs with one-step spin-coated CH3NH3PbBr3 emitter, an optimal MoO3-ammonia volume ratio (0.02) in PEDOT:PSS/MoO3-ammonia composite HTL presented a maximum luminance of 1082 cd/m2 and maximum current efficiency of 0.7 cd/A, which are 82% and 94% higher than those of the control device using pure PEDOT:PSS HTL respectively. It can be explained by that the optimized amount of MoO3-ammonia in the composite HTLs cannot only facilitate hole injection into CH3NH3PbBr3 through reducing the contact barrier, but also suppress the exciton quenching at the HTL/CH3NH3PbBr3 interface. Three-step spin coating method was further used to obtain uniform and dense CH3NH3PbBr3 films, which lead to a maximum luminance of 5044 cd/m2 and maximum current efficiency of 3.12 cd/A, showing enhancement of 750% and 767% compared with the control device respectively. The significantly improved efficiency of PeLEDs using three-step spin-coated CH3NH3PbBr3 film and an optimum PEDOT:PSS/MoO3-ammonia composite HTL can be explained by the enhanced carrier recombination through better hole injection and film morphology optimization, as well as the reduced exciton quenching at HTL/CH3NH3PbBr3 interface. These results present a promising strategy for the device engineering of high efficiency PeLEDs.

Improve the Efficiency of White Organic Light-Emitting Devices Using Double-Doped System

2010 ◽  
Vol 152-153 ◽  
pp. 687-690
Author(s):  
Gui Ying Ding ◽  
Wen Long Jiang ◽  
Guang De Wang ◽  
Qiang Han ◽  
Xi Chang
Keyword(s):  
Current Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Maximum Current ◽  
Hole Transporting ◽  
White Oleds ◽  
Organic Light Emitting Devices ◽  
20 Nm ◽  
White Oled

The doped and non-doped white Organic light-emitting devices (OLEDs) were fabricated, using strong yellow emitting and hole-transporting ability of TPAHQZn. When the white OLED is a double-doped structure, greatly enhanced the efficiency of the device. The double-doped white device were fabricated as follows: ITO/2T-NATA (17 nm)/ CBP: 30% TPAHQZn: 8% Ir(ppy)3 (25 nm)/ NPBX (15 nm)/BCP(8nm)/TPBi: 10% Ir(ppy)3 (15nm)/Alq3 (20 nm)/LiF (1.3 nm)/Al. The double-doped white OLEDs were obtained with Commission International de L’Eclairage coordinates of (0.29,0.28) at 17 V, the maximum current efficiency increaed four times that double-doped white device of 4.12cd/A(8V) than non-doped of 1.03 cd/A (10V) .

Solution-processable, high luminance deep-blue organic light emitting devices based on novel naphthalene bridged bis-triphenylamine derivatives

2019 ◽  
Vol 7 (9) ◽  
pp. 2686-2698 ◽  
Author(s):  
Yuqin Li ◽  
Siming Gao ◽  
Nan Zhang ◽  
Xin Huang ◽  
Jinchang Tian ◽  
...  
Keyword(s):  
Current Efficiency ◽  
High Luminance ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Deep Blue ◽  
Organic Light ◽  
Maximum Current ◽  
Solution Processable ◽  
Organic Light Emitting Devices ◽  
Very High

The optimal device E exhibited a very high luminance of 10 407 cd m−2 and a maximum current efficiency of 7.80 cd A−1.

Efficient electroluminescence of bluish green iridium complexes with 2-(3,5-bis(trifluoromethyl)phenyl)pyrimidine and 2-(3,5-bis(trifluoromethyl)phenyl)-5-fluoropyrimidine as the main ligands

2018 ◽  
Vol 5 (7) ◽  
pp. 1545-1552 ◽  
Author(s):  
Hua-Bo Han ◽  
Zheng-Guang Wu ◽  
You-Xuan Zheng
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Iridium Complexes ◽  
Bluish Green ◽  
Maximum Current

Four bluish green iridium complexes with high photoluminescence quantum efficiencies were applied in OLEDs, and they showed a maximum current efficiency of 74.70 cd A−1 and a maximum external quantum efficiency of 35.0% with mild efficiency roll-off.

Efficient bluish green electroluminescence of iridium complexes with good electron mobility

2018 ◽  
Vol 42 (16) ◽  
pp. 13351-13357 ◽  
Author(s):  
Hua-Bo Han ◽  
Zheng-Guang Wu ◽  
You-Xuan Zheng
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
Electron Mobility ◽  
External Quantum Efficiency ◽  
Iridium Complexes ◽  
Bluish Green ◽  
Maximum Current

Two efficient bluish green iridium complexes with good electron mobility were applied in efficient OLEDs, showing a maximum current efficiency of 71.18 cd A−1 and a maximum external quantum efficiency of 27.7%.

Refractory Periods Observed by Intrinsic Signal and Fluorescent Dye Imaging

1998 ◽  
Vol 80 (3) ◽  
pp. 1522-1532 ◽  
Author(s):  
Andrew F. Cannestra ◽  
Nader Pouratian ◽  
Marc H. Shomer ◽  
Arthur W. Toga
Keyword(s):  
Fluorescent Dyes ◽  
Imaging Techniques ◽  
Human Subjects ◽  
Fluorescent Dye ◽  
Initial Stimulus ◽  
Intrinsic Signals ◽  
Intrinsic Signal ◽  
Refractory Periods ◽  
Auditory Cortices ◽  
The Relationship

Cannestra, Andrew F., Nader Pouratian, Marc H. Shomer, and Arthur W. Toga. Refractory periods observed by intrinsic signal and fluorescent dye imaging. J. Neurophysiol. 80: 1522–1532, 1998. All perfusion-based imaging modalities depend on the relationship between neuronal and vascular activity. However, the relationship between stimulus and response was never fully characterized. With the use of optical imaging (intrinsic signals and intravascular fluorescent dyes) during repetitive stimulation paradigms, we observed reduced responses with temporally close stimuli. Cortical evoked potentials, however, did not produce the same reduced responsiveness. We therefore termed these intervals of reduced responsiveness “refractory periods.” During these refractory periods an ability to respond was retained, but at a near 60% reduction in the initial magnitude. Although increasing the initial stimulus duration lengthened the observed refractory periods, significantly novel or temporally spaced stimuli overcame them. We observed this phenomenon in both rodent and human subjects in somatosensory and auditory cortices. These results have significant implications for understanding the capacities, mechanisms, and distributions of neurovascular coupling and thereby possess relevance to all perfusion-dependent functional imaging techniques.

Synthesis and photoelectric properties of a solution-processable yellow-emitting iridium(iii) complex

2015 ◽  
Vol 39 (11) ◽  
pp. 8908-8914 ◽  
Author(s):  
Yuling Wu ◽  
Huixia Xu ◽  
Junli Yang ◽  
Jie Li ◽  
Wenqing Liang ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Spin Coating ◽  
International Commission ◽  
Maximum Brightness ◽  
Photoelectric Properties ◽  
Maximum Current ◽  
Cie Coordinates ◽  
Solution Processable

A heteroleptic iridium(iii) complex [(CzhBTZ)2Ir(fpptz)] was synthesized for efficient and stable PhOLEDs by spin-coating. It shows a maximum brightness of 9617 cd m−2, a maximum current efficiency of about 9.43 cd A−1, and International Commission on Illumination (CIE) coordinates of (0.42, 0.56).

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