Boosting the external quantum efficiency in perovskite light-emitting diodes by an exciton retrieving layer

2019 ◽  
Vol 7 (28) ◽  
pp. 8705-8711 ◽  
Author(s):  
Chunhong Gao ◽  
Ziyang Xiong ◽  
Ziqian He ◽  
Yajie Dong ◽  
Fuxing Yu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Control Devices

High-efficiency perovskite LEDs fabricated by introducing an exciton retrieving layer are demonstrated. The optimized 3D CsPbBr3 LEDs achieved 2.5-fold luminance and 3.8-fold EQE enhancements compared with the control devices.

scholarly journals Record High External Quantum Efficiency of 19.2% Achieved in Light-Emitting Diodes of Colloidal Quantum Wells Enabled by Hot-Injection Shell Growth

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Shell Growth ◽  
Light Emitting ◽  
Hot Injection ◽  
Key Factor

<p> Colloidal quantum wells (CQWs) are regarded as a new, highly promising class of optoelectronic materials thanks to their unique excitonic characteristics of high extinction coefficient and ultranarrow emission bandwidth. Although the exploration of CQWs in light-emitting diodes (LEDs) is impressive, the performance of CQW-LEDs lags far behind compared with other types of LEDs (e.g., organic LEDs, colloidal quantum-dot LEDs, and perovskite LEDs). Herein, for the first time, the authors show high-efficiency CQW-LEDs reaching close to the theoretical limit. A key factor for this high performance is the exploitation of hot-injection shell (HIS) growth of CQWs, which enables a near-unity photoluminescence quantum yield (PLQY), reduces nonradiative channels, ensures smooth films and enhances the stability. Remarkably, the PLQY remains 95% in solution and 87% in film despite rigorous cleaning. Through systematically understanding their shape-, composition- and device- engineering, the CQW-LEDs using CdSe/Cd<sub>0.25</sub>Zn<sub>0.75</sub>S core/HIS CQWs exhibit a maximum external quantum efficiency of 19.2%. Additionally, a high luminance of 23,490 cd m<sup>-2</sup>, extremely saturated red color with the Commission Internationale de L’Eclairage coordinates of (0.715, 0.283) and stable emission are obtained. The findings indicate that HIS grown CQWs enable high-performance solution-processed LEDs, which may pave the path for CQW-based display and lighting technologies.</p>

scholarly journals Record High External Quantum Efficiency of 19.2% Achieved in Light-Emitting Diodes of Colloidal Quantum Wells Enabled by Hot-Injection Shell Growth

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Shell Growth ◽  
Light Emitting ◽  
Hot Injection ◽  
Key Factor

<p> Colloidal quantum wells (CQWs) are regarded as a new, highly promising class of optoelectronic materials thanks to their unique excitonic characteristics of high extinction coefficient and ultranarrow emission bandwidth. Although the exploration of CQWs in light-emitting diodes (LEDs) is impressive, the performance of CQW-LEDs lags far behind compared with other types of LEDs (e.g., organic LEDs, colloidal quantum-dot LEDs, and perovskite LEDs). Herein, for the first time, the authors show high-efficiency CQW-LEDs reaching close to the theoretical limit. A key factor for this high performance is the exploitation of hot-injection shell (HIS) growth of CQWs, which enables a near-unity photoluminescence quantum yield (PLQY), reduces nonradiative channels, ensures smooth films and enhances the stability. Remarkably, the PLQY remains 95% in solution and 87% in film despite rigorous cleaning. Through systematically understanding their shape-, composition- and device- engineering, the CQW-LEDs using CdSe/Cd<sub>0.25</sub>Zn<sub>0.75</sub>S core/HIS CQWs exhibit a maximum external quantum efficiency of 19.2%. Additionally, a high luminance of 23,490 cd m<sup>-2</sup>, extremely saturated red color with the Commission Internationale de L’Eclairage coordinates of (0.715, 0.283) and stable emission are obtained. The findings indicate that HIS grown CQWs enable high-performance solution-processed LEDs, which may pave the path for CQW-based display and lighting technologies.</p>

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.

Non-halogenated solvent-processed highly efficient green Ir(iii) complexes with an external quantum efficiency exceeding 23% for phosphorescent organic light-emitting diodes

2020 ◽  
Vol 8 (37) ◽  
pp. 12959-12967
Author(s):  
Raja Kumaresan ◽  
Athithan Maheshwaran ◽  
Ho-Yeol Park ◽  
Kyungmin Sung ◽  
Jungmin Choi ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Highly Efficient ◽  
Organic Light

High efficiency green phosphorescent Ir(III) complexes with solubilizing groups introduced to enable non-halogenated solvent-based fabrication of PHOLEDs with high EQE and CE values.

The structure optimization of phenanthroimidazole based isomers with external quantum efficiency approaching 7% in non-doped deep-blue OLEDs

2020 ◽  
Vol 8 (9) ◽  
pp. 2975-2984 ◽  
Author(s):  
Jie-Ji Zhu ◽  
Yuwen Chen ◽  
Yong-Hong Xiao ◽  
Xin Lian ◽  
Guo-Xi Yang ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Structure Optimization ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Deep Blue ◽  
Organic Light

In this work, four phenanthroimidazole (PI) based isomers TPA-PPI-PBI, TPA-PPI-NPBI, PBI-PPI-TPA and NPBI-PPI-TPA for high-efficiency deep-blue organic light-emitting diodes (OLEDs) have been designed and synthesized.

Reduced efficiency roll-off in all-phosphorescent white organic light-emitting diodes with an external quantum efficiency of over 20%

2015 ◽  
Vol 3 (14) ◽  
pp. 3304-3310 ◽  
Author(s):  
Liping Zhu ◽  
Zhongbin Wu ◽  
Jiangshan Chen ◽  
Dongge Ma
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Rational Design ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

A rational design of the emission layers to achieve a high efficiency WOLED with reduced roll-off.

High-efficiency red organic light-emitting diodes based on a double-emissive layer with an external quantum efficiency over 30%

2018 ◽  
Vol 6 (26) ◽  
pp. 7042-7045 ◽  
Author(s):  
Yanping Wang ◽  
Wenjie Wang ◽  
Zhaoji Huang ◽  
Huahang Wang ◽  
Junting Zhao ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Emissive Layer ◽  
Organic Light ◽  
Red Oleds

Red OLEDs (devices D1–D3) with a S-EML and a D-EML have been demonstrated to have different EQEs.

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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