scholarly journals Beating the Limitation of Energy Gap Law Utilizing Deep Red MR-TADF Emitter with Narrow Energy-Bandwidth

2020 ◽  
Author(s):  
Yuewei Zhang ◽  
Dongdong Zhang ◽  
Tianyu Huang ◽  
Guomeng Li ◽  
Chen Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Energy Gap ◽  
Organic Light Emitting Diodes ◽  
Vibrational Coupling ◽  
Light Emitting ◽  
Radiative Processes ◽  
Energy Gap Law ◽  
Mr Effect ◽  
Peripheral Skeleton

<p><b>The development of high-performance deep red/near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. </b><b>Herein, a novel BN-containing skeleton featuring linear N-π-N and B-π-B structure is developed, establishing partial </b><b>bonding/antibonding character on phenyl core for enhanced electronics coupling of para-positioned B atoms as well as N atoms to narrow energy gaps. Also, the remained MR effect on the peripheral skeleton to maintain the MR effect to minimize the bonding/ antibonding character and suppress vibrational coupling between S<sub>0</sub> and S<sub>1</sub>, thereby </b><b>fundamentally</b><b> overcoming the luminescent boundary set by the energy gap law. The target</b><b> molecules </b><b>R-BN and R-TBN exhibited extremely high</b><b> PLQYs of 100% with </b><b>emission wavelengths at 666 and 686 nm,</b><b> respectively. The narrow FWMHs of 38 nm observed also testify the effectiveness of vibronic suppression. The corresponding OLEDs afford</b><b> </b><b>record-high</b><b> EQEs over 28% with emission wavelength over 664 nm</b><b>. </b><b></b></p>

scholarly journals Beating the Limitation of Energy Gap Law Utilizing Deep Red MR-TADF Emitter with Narrow Energy-Bandwidth

2020 ◽  
Author(s):  
Yuewei Zhang ◽  
Dongdong Zhang ◽  
Tianyu Huang ◽  
Guomeng Li ◽  
Chen Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Energy Gap ◽  
Organic Light Emitting Diodes ◽  
Vibrational Coupling ◽  
Light Emitting ◽  
Radiative Processes ◽  
Energy Gap Law ◽  
Mr Effect ◽  
Peripheral Skeleton

<p><b>The development of high-performance deep red/near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. </b><b>Herein, a novel BN-containing skeleton featuring linear N-π-N and B-π-B structure is developed, establishing partial </b><b>bonding/antibonding character on phenyl core for enhanced electronics coupling of para-positioned B atoms as well as N atoms to narrow energy gaps. Also, the remained MR effect on the peripheral skeleton to maintain the MR effect to minimize the bonding/ antibonding character and suppress vibrational coupling between S<sub>0</sub> and S<sub>1</sub>, thereby </b><b>fundamentally</b><b> overcoming the luminescent boundary set by the energy gap law. The target</b><b> molecules </b><b>R-BN and R-TBN exhibited extremely high</b><b> PLQYs of 100% with </b><b>emission wavelengths at 666 and 686 nm,</b><b> respectively. The narrow FWMHs of 38 nm observed also testify the effectiveness of vibronic suppression. The corresponding OLEDs afford</b><b> </b><b>record-high</b><b> EQEs over 28% with emission wavelength over 664 nm</b><b>. </b><b></b></p>

Near infrared to visible light organic up-conversion devices with photon-to-photon conversion efficiency approaching 30%

2018 ◽  
Vol 5 (5) ◽  
pp. 874-882 ◽  
Author(s):  
Dezhi Yang ◽  
Xiaokang Zhou ◽  
Dongge Ma ◽  
Agafonov Vadim ◽  
Tansir Ahamad ◽  
...  
Keyword(s):  
Visible Light ◽  
Conversion Efficiency ◽  
High Performance ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Photon Conversion

High performance organic up-conversion devices are developed by integrating near infrared polymer photodetectors and tandem organic light emitting diodes.

scholarly journals Towards efficient near-infrared fluorescent organic light-emitting diodes

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Alessandro Minotto ◽  
Ibrahim Bulut ◽  
Alexandros G. Rapidis ◽  
Giuseppe Carnicella ◽  
Maddalena Patrini ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Energy Gap ◽  
Internal Quantum Efficiency ◽  
Organic Light Emitting Diodes ◽  
General Strategy ◽  
Light Emitting ◽  
Organic Light ◽  
Radiative Rate

AbstractThe energy gap law (EG-law) and aggregation quenching are the main limitations to overcome in the design of near-infrared (NIR) organic emitters. Here, we achieve unprecedented results by synergistically addressing both of these limitations. First, we propose porphyrin oligomers with increasing length to attenuate the effects of the EG -law by suppressing the non-radiative rate growth, and to increase the radiative rate via enhancement of the oscillator strength. Second, we design side chains to suppress aggregation quenching. We find that the logarithmic rate of variation in the non-radiative rate vs. EG is suppressed by an order of magnitude with respect to previous studies, and we complement this breakthrough by demonstrating organic light-emitting diodes with an average external quantum efficiency of ~1.1%, which is very promising for a heavy-metal-free 850 nm emitter. We also present a novel quantitative model of the internal quantum efficiency for active layers supporting triplet-to-singlet conversion. These results provide a general strategy for designing high-luminance NIR emitters.

Ultra-smooth and robust graphene-based hybrid anode for high-performance flexible organic light-emitting diodes

2021 ◽  
Author(s):  
zhikun zhang ◽  
lianlian xia ◽  
Lizhao Liu ◽  
Yuwen Chen ◽  
zuozhi wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Chemical Vapor ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Large Particles

Large surface roughness, especially caused by the large particles generated during both the transfer and the doping processes of graphene grown by chemical vapor deposition (CVD) is always a critical...

High performance red phosphorescent organic electroluminescent devices with characteristic mechanisms by utilizing terbium or gadolinium complexes as sensitizers

2017 ◽  
Vol 5 (8) ◽  
pp. 2066-2073 ◽  
Author(s):  
Rongzhen Cui ◽  
Weiqiang Liu ◽  
Liang Zhou ◽  
Xuesen Zhao ◽  
Yunlong Jiang ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Color Purity ◽  
Electroluminescent Devices ◽  
Light Emitting ◽  
Organic Light ◽  
Gadolinium Complexes ◽  
Organic Electroluminescent ◽  
High Color Purity

High performance sensitized organic light-emitting diodes with high color purity were obtained by utilizing terbium or gadolinium complexes as sensitizers.

Electrically driven single microribbon based near-infrared exciton-polariton light-emitting diode

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mingming Jiang ◽  
Fupeng Zhang ◽  
Kai Tang ◽  
Peng Wan ◽  
Caixia Kan
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Coherent Light ◽  
Light Emitting ◽  
Exciton Polaritons ◽  
Laser Devices

Achieving electrically-driven exciton-polaritons has drawn substantial attention toward developing ultralow-threshold coherent light sources, containing polariton laser devices and high-performance light-emitting diodes (LEDs). In this work, we demonstrate an electrically driven...

scholarly journals Universal Electroluminescence at Voltages below the Energy Gap in Organic Light‐Emitting Diodes

2021 ◽  
pp. 2101149
Author(s):  
Yungui Li ◽  
Oskar Sachnik ◽  
Bas Zee ◽  
Kalyani Thakur ◽  
Charusheela Ramanan ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Energy Gap ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light
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