scholarly journals Inhibited nonradiative decay at all exciton densities in monolayer semiconductors

Science ◽  
2021 ◽  
Vol 373 (6553) ◽  
pp. 448-452
Author(s):  
Hyungjin Kim ◽  
Shiekh Zia Uddin ◽  
Naoki Higashitarumizu ◽  
Eran Rabani ◽  
Ali Javey
Keyword(s):  
High Efficiency ◽  
Defect Density ◽  
Mechanical Strain ◽  
Transition Metal Dichalcogenide ◽  
Nonradiative Recombination ◽  
Light Emitting ◽  
Practical Applications ◽  
Light Emitting Devices ◽  
Performance Metric ◽  
Exciton Annihilation

Most optoelectronic devices operate at high photocarrier densities, where all semiconductors suffer from enhanced nonradiative recombination. Nonradiative processes proportionately reduce photoluminescence (PL) quantum yield (QY), a performance metric that directly dictates the maximum device efficiency. Although transition metal dichalcogenide (TMDC) monolayers exhibit near-unity PL QY at low exciton densities, nonradiative exciton-exciton annihilation (EEA) enhanced by van-Hove singularity (VHS) rapidly degrades their PL QY at high exciton densities and limits their utility in practical applications. Here, by applying small mechanical strain (less than 1%), we circumvented VHS resonance and markedly suppressed EEA in monolayer TMDCs, resulting in near-unity PL QY at all exciton densities despite the presence of a high native defect density. Our findings can enable light-emitting devices that retain high efficiency at all brightness levels.

scholarly journals Efficient and large-area all vacuum-deposited perovskite light-emitting diodes via spatial confinement

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peipei Du ◽  
Jinghui Li ◽  
Liang Wang ◽  
Liang Sun ◽  
Xi Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Scale Production ◽  
Nonradiative Recombination ◽  
Large Area ◽  
Spatial Confinement ◽  
Light Emitting ◽  
Large Scale Production

AbstractWith rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.

High-efficiency blue and white organic light-emitting devices by combining fluorescent and phosphorescent blue emitters

2012 ◽  
Vol 13 (11) ◽  
pp. 2412-2416 ◽  
Author(s):  
Xuecheng Piao ◽  
Yongming Yin ◽  
Jian Liu ◽  
Yang Li ◽  
Kai Xu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Blue Emitters ◽  
Organic Light Emitting Devices

Ultra High Efficiency Green Organic Light-Emitting Devices

2006 ◽  
Vol 46 (1) ◽  
pp. L10-L12 ◽  
Author(s):  
Daisaku Tanaka ◽  
Hisahiro Sasabe ◽  
Yan-Jun Li ◽  
Shi-Jian Su ◽  
Takashi Takeda ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices

High-efficiency and good color quality white light-emitting devices based on polymer blend

2009 ◽  
Vol 10 (5) ◽  
pp. 843-848 ◽  
Author(s):  
Jianhua Zou ◽  
Jie Liu ◽  
Hongbin Wu ◽  
Wei Yang ◽  
Junbiao Peng ◽  
...  
Keyword(s):  
Polymer Blend ◽  
White Light ◽  
High Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Color Quality

High-efficiency phosphorescent polymer light-emitting devices

2003 ◽  
Vol 4 (2-3) ◽  
pp. 105-111 ◽  
Author(s):  
Shizuo Tokito ◽  
Mitsunori Suzuki ◽  
Fumio Sato ◽  
Motoaki Kamachi ◽  
Kourou Shirane
Keyword(s):  
High Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Polymer Light Emitting Devices

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.

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