scholarly journals Improving hole injection from p-EBL down to the end of active region by simply playing with polarization effect for AlGaN based DUV light-emitting diodes

AIP Advances ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 065032
Author(s):  
Danyang Zhang ◽  
Chunshuang Chu ◽  
Kangkai Tian ◽  
Jianquan Kou ◽  
Wengang Bi ◽  
...  
Keyword(s):  
Active Region ◽  
Polarization Effect ◽  
Light Emitting Diodes ◽  
Hole Injection ◽  
Light Emitting

scholarly journals Improved Performance of Electron Blocking Layer Free AlGaN Deep Ultraviolet Light-Emitting Diodes Using Graded Staircase Barriers

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Barsha Jain ◽  
Ravi Teja Velpula ◽  
Moulik Patel ◽  
Sharif Md. Sadaf ◽  
Hieu Pham Trung Nguyen
Keyword(s):  
Active Region ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Hole Injection ◽  
Blocking Layer ◽  
Electron Blocking Layer ◽  
Injection Efficiency ◽  
Light Emitting ◽  
Electron Leakage ◽  
Deep Ultraviolet

To prevent electron leakage in deep ultraviolet (UV) AlGaN light-emitting diodes (LEDs), Al-rich p-type AlxGa(1−x)N electron blocking layer (EBL) has been utilized. However, the conventional EBL can mitigate the electron overflow only up to some extent and adversely, holes are depleted in the EBL due to the formation of positive sheet polarization charges at the heterointerface of the last quantum barrier (QB)/EBL. Subsequently, the hole injection efficiency of the LED is severely limited. In this regard, we propose an EBL-free AlGaN deep UV LED structure using graded staircase quantum barriers (GSQBs) instead of conventional QBs without affecting the hole injection efficiency. The reported structure exhibits significantly reduced thermal velocity and mean free path of electrons in the active region, thus greatly confines the electrons over there and tremendously decreases the electron leakage into the p-region. Moreover, such specially designed QBs reduce the quantum-confined Stark effect in the active region, thereby improves the electron and hole wavefunctions overlap. As a result, both the internal quantum efficiency and output power of the GSQB structure are ~2.13 times higher than the conventional structure at 60 mA. Importantly, our proposed structure exhibits only ~20.68% efficiency droop during 0–60 mA injection current, which is significantly lower compared to the regular structure.

EFFICIENCY DROOP IN GaInN HIGH-POWER LIGHT-EMITTING DIODES

2011 ◽  
Vol 20 (02) ◽  
pp. 247-265 ◽  
Author(s):  
MARTIN F. SCHUBERT ◽  
JONG KYU KIM
Keyword(s):  
Active Region ◽  
Auger Recombination ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Efficiency Droop ◽  
Hole Injection ◽  
Light Emitting ◽  
High Drive ◽  
Device Structures ◽  
Substantial Effort

GaN -based light-emitting diodes suffer from high-current loss mechanisms that lead to a significant decrease in internal quantum efficiency at high drive currents. This phenomenon, known as "efficiency droop," is a major problem for solid-state lighting applications, in which light-emitting diodes are driven at high currents to deliver large optical powers. Although substantial effort has been invested to uncover the physical origin and mitigate the effects of efficiency droop, there is still a lack of consensus on the dominant mechanism responsible. In this article, we review several mechanisms that have been proposed as explanations of efficiency droop, including junction heating, carrier delocalization, Auger recombination, and electron leakage from the active region. In addition, device structures intended to mitigate the droop-causing mechanism – (i) thick quantum wellsl, (ii) enhanced hole-injection efficiency structures, and (iii) polarization-matched active region – are discussed.

High efficiency tunneling-regenerated multi-active region light-emitting diodes

2000 ◽  
Author(s):  
Xia Guo ◽  
Guangdi Shen ◽  
Guohong Wang ◽  
Jinyu Du ◽  
WeiLing Guo ◽  
...  
Keyword(s):  
Active Region ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Emitting

High performance organic light emitting diodes using substoichiometric tungsten oxide as efficient hole injection layer

2012 ◽  
Vol 13 (5) ◽  
pp. 796-806 ◽  
Author(s):  
Maria Vasilopoulou ◽  
George Papadimitropoulos ◽  
Leonidas C. Palilis ◽  
Dimitra G. Georgiadou ◽  
Panagiotis Argitis ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Hole Injection ◽  
Light Emitting ◽  
Hole Injection Layer ◽  
Organic Light

scholarly journals Enhanced hole injection in organic light-emitting diodes utilizing a copper iodide-doped hole injection layer

RSC Advances ◽  
2017 ◽  
Vol 7 (22) ◽  
pp. 13584-13589 ◽  
Author(s):  
Meiling Shan ◽  
Haipeng Jiang ◽  
Yu Guan ◽  
Dongsu Sun ◽  
Yu Wang ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Hole Injection ◽  
Copper Iodide ◽  
Light Emitting ◽  
Hole Injection Layer ◽  
Organic Light

We have demonstrated organic light-emitting diodes (OLEDs) by incorporating copper iodide (CuI) in 4,4′,4′′-tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine (m-MTDATA) as a hole injection layer (HIL) based on the emitting system of C545T–Alq3.

Stable solution processed hole injection material for organic light-emitting diodes

2014 ◽  
Vol 15 (10) ◽  
pp. 2513-2517 ◽  
Author(s):  
Szuheng Ho ◽  
Chaoyu Xiang ◽  
Rui Liu ◽  
Neetu Chopra ◽  
Mathew Mathai ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Stable Solution ◽  
Organic Light Emitting Diodes ◽  
Hole Injection ◽  
Solution Processed ◽  
Light Emitting ◽  
Injection Material ◽  
Organic Light

Efficient perovskite light-emitting diodes with modified hole injection layer

2021 ◽  
Author(s):  
Shuo Sun ◽  
Junjie Si ◽  
Zugang Liu ◽  
Rui Xu ◽  
Yihang Du ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Hole Injection ◽  
Light Emitting ◽  
Hole Injection Layer
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