Nearly 100% Internal Quantum Efficiency in an Organic Blue-Light Electrophosphorescent Device Using a Weak Electron Transporting Material with a Wide Energy Gap

2009 ◽  
Vol 21 (12) ◽  
pp. 1271-1274 ◽  
Author(s):  
Lixin Xiao ◽  
Shi-Jian Su ◽  
Yuya Agata ◽  
Hsinglin Lan ◽  
Junji Kido
Keyword(s):  
Blue Light ◽  
Quantum Efficiency ◽  
Energy Gap ◽  
Internal Quantum Efficiency ◽  
Wide Energy ◽  
Weak Electron

Photoelectrical Properties and Energetical Structure of Thin Films of Indandione Derivatives

1970 ◽  
Vol 17 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Maira INDRIKOVA ◽  
Janis LATVELS ◽  
Inta MUZIKANTE ◽  
Baiba TUROVSKA
Keyword(s):  
Quantum Efficiency ◽  
Energy Gap ◽  
Calculated Data ◽  
Combined System ◽  
High Quantum Efficiency ◽  
Solar Systems ◽  
Photoelectrical Properties ◽  
Sandwich Type ◽  
Wide Energy ◽  
Homo And Lumo

A sandwich type structure of two dimetilaminobenziliden-1,3-indandione (DMABI) derivatives placed between metal electrodes was made to investigate the photoelectrical properties of these derivatives. DMABI is an organic isolator with a wide energy gap and high quantum efficiency of the photogeneration, DMABI derivatives have received also considerable attention because of its large dipole moment and optical nonlinearities. Besides, since it is a photosensitive material, its use in solar systems is very promising. The energy gap of each material and combined system was observed from the spectral dependence of the quantum efficiency of the photoconductivity and results are compared with results of oxidation and reduction potential of the materials. The values showed a good correlation between experimental data of the photoconductivity and voltamperometry and calculated data of the HOMO and LUMO levels of the molecules.http://dx.doi.org/10.5755/j01.ms.17.2.480

High Internal Quantum Efficiency Blue Light-emitting Diodes with Triangular Shaped InGaN/GaN Multiple Quantum Wells

2013 ◽  
Vol 34 (1) ◽  
pp. 66-72
Author(s):  
赵芳 ZHAO Fang ◽  
张运炎 ZHANG Yun-yan ◽  
宋晶晶 SONG Jing-jing ◽  
丁彬彬 DING Bin-bin ◽  
范广涵 FAN Guang-han
Keyword(s):  
Quantum Wells ◽  
Blue Light ◽  
Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Light Emitting

Theoretical investigation of Auger recombination on internal quantum efficiency of blue light-emitting diodes

2009 ◽  
Vol 97 (3) ◽  
pp. 705-708 ◽  
Author(s):  
S.-H. Yen ◽  
M.-C. Tsai ◽  
M.-L. Tsai ◽  
Y.-J. Shen ◽  
T.-C. Hsu ◽  
...  
Keyword(s):  
Blue Light ◽  
Quantum Efficiency ◽  
Theoretical Investigation ◽  
Auger Recombination ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Light Emitting

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.

scholarly journals Perspectives on UVC LED: Its Progress and Application

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 196
Author(s):  
Tsung-Chi Hsu ◽  
Yu-Tsai Teng ◽  
Yen-Wei Yeh ◽  
Xiaotong Fan ◽  
Kuo-Hsiung Chu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Flip Chip ◽  
Layer Structure ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Reverse Current ◽  
Light Extraction ◽  
Epitaxial Layers ◽  
High Electron ◽  
Recombination Rates

High-quality epitaxial layers are directly related to internal quantum efficiency. The methods used to design such epitaxial layers are reviewed in this article. The ultraviolet C (UVC) light-emitting diode (LED) epitaxial layer structure exhibits electron leakage; therefore, many research groups have proposed the design of blocking layers and carrier transportation to generate high electron–hole recombination rates. This also aids in increasing the internal quantum efficiency. The cap layer, p-GaN, exhibits high absorption in deep UV radiation; thus, a small thickness is usually chosen. Flip chip design is more popular for such devices in the UV band, and the main factors for consideration are light extraction and heat transportation. However, the choice of encapsulation materials is important, because unsuitable encapsulation materials will be degraded by ultraviolet light irradiation. A suitable package design can account for light extraction and heat transportation. Finally, an atomic layer deposition Al2O3 film has been proposed as a mesa passivation layer. It can provide a low reverse current leakage. Moreover, it can help increase the quantum efficiency, enhance the moisture resistance, and improve reliability. UVC LED applications can be used in sterilization, water purification, air purification, and medical and military fields.

The novel Sr3LiSbO6:Mn4+, Ca2+ far-red-emitting phosphors with over 95% internal quantum efficiency for indoor plant growth LEDs

2021 ◽  
Vol 237 ◽  
pp. 118165
Author(s):  
Linyan Fu ◽  
Yunlong Yang ◽  
Yi Zhang ◽  
Xuefei Ren ◽  
Yingjie Zhu ◽  
...  
Keyword(s):  
Plant Growth ◽  
Quantum Efficiency ◽  
Internal Quantum Efficiency ◽  
The Novel
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