Exciton localization and quantum efficiency—A comparative cathodoluminescence study of (In,Ga)N/GaN and GaN/(Al,Ga)N quantum wells

2003 ◽  
Vol 93 (2) ◽  
pp. 1048-1053 ◽  
Author(s):  
U. Jahn ◽  
S. Dhar ◽  
O. Brandt ◽  
H. T. Grahn ◽  
K. H. Ploog ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Exciton Localization ◽  
Cathodoluminescence Study

Microroughness and exciton localization in (Al,Ga)As/GaAs quantum wells

1997 ◽  
Vol 55 (8) ◽  
pp. 5253-5258 ◽  
Author(s):  
R. Grousson ◽  
V. Voliotis ◽  
N. Grandjean ◽  
J. Massies ◽  
M. Leroux ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Exciton Localization

Exciton localization inInxGa1−xAs/GaAs quantum wells observed by temperature-modulated photoluminescence

1991 ◽  
Vol 43 (2) ◽  
pp. 1546-1550 ◽  
Author(s):  
M. Gal ◽  
Z. Y. Xu ◽  
F. Green ◽  
B. F. Usher
Keyword(s):  
Quantum Wells ◽  
Exciton Localization

Optical Study of Localized and Delocalized States in GaAsN/GaAs

2003 ◽  
Vol 798 ◽  
Author(s):  
Z. Y. Xu ◽  
X. D. Luo ◽  
X. D. Yang ◽  
P. H. Tan ◽  
C. L. Yang ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Rapid Thermal Annealing ◽  
Short Pulse ◽  
Selective Excitation ◽  
Excitation Power ◽  
Pulse Excitation ◽  
Optical Study ◽  
Time Resolved ◽  
Exciton Localization ◽  
Time Resolved Photoluminescence

ABSTRACTTaking advantages of short pulse excitation and time-resolved photoluminescence (PL), we have studied the exciton localization effect in a number of GaAsN alloys and GaAsN/GaAs quantum wells (QWs). In the PL spectra, an extra transition located at the higher energy side of the commonly reported N-related emissions is observed. By measuring PL dependence on temperature and excitation power along with PL dynamics study, the new PL peak has been identified as a transition of the band edge-related recombination in dilute GaAsN alloy and delocalized transition in QWs. Using selective excitation PL we further attribute the localized emission in QWs to the excitons localized at the GaAsN/GaAs interfaces. This interface-related exciton localization could be greatly reduced by a rapid thermal annealing.

Exciton localization in group-III nitride quantum wells

1999 ◽  
Vol 59 (15) ◽  
pp. 9783-9786 ◽  
Author(s):  
V. I. Litvinov ◽  
M. Razeghi
Keyword(s):  
Quantum Wells ◽  
Group Iii ◽  
Exciton Localization ◽  
Group Iii Nitride

scholarly journals Record High External Quantum Efficiency of 19.2% Achieved in Light-Emitting Diodes of Colloidal Quantum Wells Enabled by Hot-Injection Shell Growth

2019 ◽  
Author(s):  
Baiquan Liu ◽  
Yemliha Altintas ◽  
Lin Wang ◽  
Sushant Shendre ◽  
Manoj Sharma ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Shell Growth ◽  
Light Emitting ◽  
Hot Injection ◽  
Key Factor

<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>

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