scholarly journals Perovskite Light-Emitting Devices with Doped Hole Transporting Layer

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1670
Author(s):  
Zhiwei Peng ◽  
Yuhan Gao ◽  
Guohua Xie
Keyword(s):  
Quantum Dots ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Control Device ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Improvement Factor ◽  
Hole Transporting ◽  
Perovskite Quantum Dots

Perovskite quantum dots (PQDs) have drawn global attention in recent years and have been used in a range of semiconductor devices, especially for light-emitting diodes (LEDs). However, because of the nature of low-conductive ligands of PQDs and surface and bulk defects in the devices, charge injection and transport should be carefully managed in order to maximize the electroluminescent performances. In this study, we employed three p-dopants, i.e., 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), 1,3,4,5,7,8-hexafluoro-11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (F6-TCNNQ), and 11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (TCNH14), respectively doped into the commonly used hole transporting layer (HTL) poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA). Compared with the devices with the neat PTAA, those with the doped PTAA as the HTLs achieved the improved electroluminescent performances. In particular, the device with the strong oxidant F4-TCNQ exhibited an improvement factor of 27% in the peak external quantum efficiency compared with the control device with the neat PTAA. The capacitance and transient electroluminescent measurements were carried out to identify the imperceptible interactions in the doped HTL and at the interface between the HTL and PQDs.

High-efficiency, deep blue ZnCdS/CdxZn1−xS/ZnS quantum-dot-light-emitting devices with an EQE exceeding 18%

Nanoscale ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 5650-5657 ◽  
Author(s):  
Ouyang Wang ◽  
Lei Wang ◽  
Zhaohan Li ◽  
Qiulei Xu ◽  
Qingli Lin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Deep Blue

18% peak external quantum efficiency (EQE) for deep blue QLEDs by using ZnCdS/CdxZn1−xS/ZnS quantum dots.

High-efficiency quantum dot light-emitting diodes employing lithium salt doped poly(9-vinlycarbazole) as a hole-transporting layer

2017 ◽  
Vol 5 (22) ◽  
pp. 5372-5377 ◽  
Author(s):  
Ying-Li Shi ◽  
Feng Liang ◽  
Yun Hu ◽  
Xue-Dong Wang ◽  
Zhao-Kui Wang ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Lithium Salt ◽  
Light Emitting ◽  
Hole Transporting

The maximum external quantum efficiency of the device is 11.46% using PVK doped Li-TFSI as the hole-transporting layer.

Near-infrared light emitting diodes using PbSe quantum dots

RSC Advances ◽  
2015 ◽  
Vol 5 (67) ◽  
pp. 54109-54114 ◽  
Author(s):  
Long Yan ◽  
Xinyu Shen ◽  
Yu Zhang ◽  
Tieqiang Zhang ◽  
Xiaoyu Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Light Emitting

The near-infrared light-emitting diodes using PbSe quantum dots were fabricated with the highest external quantum efficiency of 2.52%, which is comparable to those commercial InGaAsP LEDs and visible quantum dot electroluminescence LEDs.

Organic–inorganic hybrid perovskite quantum dots for light-emitting diodes

2018 ◽  
Vol 6 (18) ◽  
pp. 4831-4841 ◽  
Author(s):  
Wei Deng ◽  
Huan Fang ◽  
Xiangcheng Jin ◽  
Xiujuan Zhang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Narrow Band ◽  
Optoelectronic Properties ◽  
Next Generation ◽  
Inorganic Hybrid ◽  
Light Emitting ◽  
Hybrid Perovskite ◽  
Perovskite Quantum Dots

Organic–inorganic hybrid perovskite (CH3NH3PbX3, X = Cl, Br, or I) quantum dots with superior optoelectronic properties, including bright, colour-tunable, narrow-band photoluminescence and high photoluminescence quantum efficiency, are regarded as ideal materials for next-generation displays.

Combinatorial Fabrication and Studies of Small Molecular Organic Light-Emitting

2003 ◽  
Vol 804 ◽  
Author(s):  
Devices G. Li ◽  
L. Zou ◽  
K. O. Cheon ◽  
J. Shinar
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Emission Layer ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Host Layer ◽  
Organic Light ◽  
Hole Transporting ◽  
Matrix Arrays ◽  
A Current

ABSTRACTVarious combinatorial matrix arrays of UV-violet, white, and blue-to-red organic light-emitting devices (OLEDs), fabricated using a sliding shutter technique, are described. In the UV-violet devices, which contain a UV-violet emitting layer of 4,4′-bis(9-carbazolyl) biphenyl (CBP), the optimal radiance R and external quantum efficiency ηext were determined with respect to the thicknesses of the hole transporting layers. In the blue-to-red devices, which contained a blue-emitting layer of 4,4′-bis(2,2′-diphenyl-vinyl) -1,1′-biphenyl (DPVBi) and a red-emitting 5 wt.% dye-doped guest-host layer, the color of the devices evolved continuously from blue to red as the thickness of the doped layer increased from 0 to 35 Å. The (nominal) 2 Å-thick doped layer device exhibited the highest brightness L ∼ 120 Cd/m2 and external quantum efficiency ηext ∼4.4 % at a current density of 1 mA/cm2. In the white OLEDs, which were similar to the blue-to-red devices but with lightly doped emission layer, the highest brightness Lmax was over 74,000 Cd/m2; in all devices Lmax exceeded 50,000 Cd/m2. The maximum efficiencies were 11.0 Cd/A, 5.96 lm/W and 4.6% at 5.8 V, 0.6 mA/cm2, and 68 Cd/m2 in a 0.25 wt.%, 2 nm-thick doped layer device.

scholarly journals Phenylalkylammonium passivation enables perovskite light emitting diodes with record high-radiance operational lifetime: the chain length matters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuwei Guo ◽  
Sofia Apergi ◽  
Nan Li ◽  
Mengyu Chen ◽  
Chunyang Yin ◽  
...  
Keyword(s):  
Chain Length ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Surface Defects ◽  
Theoretical Modelling ◽  
Ion Migration ◽  
Light Emitting ◽  
Operational Lifetime ◽  
Chain Lengths

AbstractPerovskite light emitting diodes suffer from poor operational stability, exhibiting a rapid decay of external quantum efficiency within minutes to hours after turn-on. To address this issue, we explore surface treatment of perovskite films with phenylalkylammonium iodide molecules of varying alkyl chain lengths. Combining experimental characterization and theoretical modelling, we show that these molecules stabilize the perovskite through suppression of iodide ion migration. The stabilization effect is enhanced with increasing chain length due to the stronger binding of the molecules with the perovskite surface, as well as the increased steric hindrance to reconfiguration for accommodating ion migration. The passivation also reduces the surface defects, resulting in a high radiance and delayed roll-off of external quantum efficiency. Using the optimized passivation molecule, phenylpropylammonium iodide, we achieve devices with an efficiency of 17.5%, a radiance of 1282.8 W sr−1 m−2 and a record T50 half-lifetime of 130 h under 100 mA cm−2.

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