scholarly journals Температурное падение эффективности мощных синих InGaN/GaN-светодиодов

Author(s):  
Н.М. Шмидт ◽  
Е.И. Шабунина ◽  
А.Е. Черняков ◽  
А.Е. Иванов ◽  
Н.А. Тальнишних ◽  
...  

The thermal droop of external quantum efficiency (EQE) at maximum in blue InGaN/GaN LEDs at j < 10 A/cm2 is caused by increasing losses related to non-radiative recombination due to carrier tunneling with the assistance of phonons and traps, enhancing by a temperature growth up to 400 K. When a p-n junction opens at j > 40 A/cm2, the EQE droop under direct current and at pulse mode is due to the losses associated with non-equilibrium filling of the states related to lateral alloy non-uniformities in quantum wells situated outside of the depletion region by delocalized carriers as well as the losses due to the interactions between delocalized carriers and extended defects.

1998 ◽  
Vol 41 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Vladislav B Timofeev ◽  
A V Larionov ◽  
J Zeman ◽  
G Martinez ◽  
J Hvam ◽  
...  

2007 ◽  
Vol 49 (6) ◽  
pp. 1175-1183 ◽  
Author(s):  
V. F. Agekyan ◽  
I. Akai ◽  
N. N. Vasil’ev ◽  
T. Karasawa ◽  
G. Karczewski ◽  
...  

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  

<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>


1999 ◽  
Vol 38 (Part 1, No. 4B) ◽  
pp. 2552-2554 ◽  
Author(s):  
Koji Kawasaki ◽  
Masaaki Imazawa ◽  
Toshio Imanishi ◽  
Kenji Kawashima ◽  
Kenzo Fujiwara ◽  
...  

Author(s):  
B. Sermage ◽  
K. Satzke ◽  
C. Dumas ◽  
N. Roy ◽  
B. Deveaud ◽  
...  

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