GaAs/GaAsP nanowires containing quantum wells or dots for high-efficiency light-emitters (Conference Presentation)

2019 ◽  
Author(s):  
David J. Mowbray
Keyword(s):  
Quantum Wells ◽  
High Efficiency ◽  
Light Emitters

Fabrication and Optical Properties of Green emission semipolar {101̅1} InGaN/GaN MQWs Selective Grown on GaN Nanopyramid Arrays

2011 ◽  
Vol 1324 ◽  
Author(s):  
Shih-Pang Chang ◽  
Jet-Rung Chang ◽  
Ji-Kai Huang ◽  
Jinchai Li ◽  
Yi-Chen Chen ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Efficiency ◽  
Internal Quantum Efficiency ◽  
Green Emission ◽  
Multiple Quantum ◽  
Internal Electric Field ◽  
Nonradiative Recombination ◽  
Light Emitters ◽  
Selective Area Epitaxy ◽  
Transmission Electron

AbstractWe report that the high crystalline and high efficiency green emission semipolar {101̅1} InGaN/GaN multiple quantum wells (MQWs) grown on the {101̅1} facets of GaN nanopyramid arrays by selective area epitaxy. Clear and sharp interfaces of the semipolar {101̅1} InGaN/GaN MQWs was observed by transmission electron microscopy images. As comparing with (0001) MQWs, the internal electric field of {101̅1} MQWs was remarkably reduced from 1.7 MV/cm to 0.5 MV/cm, and the room temperature (RT) internal quantum efficiency (IQE) at green emission was enhanced by about 80%. This greatly enhancement of IQE is due to suppress the polarization effect in the {101̅1} MQWs which shorten the radiative recombination to compete with nonradiative recombination at RT. These results evince that the {101̅1} planes are promising for solving the efficiency green gap of III-nitride light emitters.

MICROCAVITIES, PHOTONIC CRYSTALS AND SEMICONDUCTORS: FROM BASIC PHYSICS TO APPLICATIONS IN LIGHT EMITTERS

2000 ◽  
Vol 10 (01) ◽  
pp. 339-354 ◽  
Author(s):  
C. WEISBUCH ◽  
H. BENISTY ◽  
R. HOUDRÉ
Keyword(s):  
Quantum Dots ◽  
Photonic Crystals ◽  
Quantum Wells ◽  
High Efficiency ◽  
Purcell Effect ◽  
Confined Systems ◽  
Light Emitters ◽  
Strong Light ◽  
Matter Coupling ◽  
Basic Physics

Photon confined systems in the form of microcavities and photonic crystals overcome the main stumbling block to high efficiency light emitters, i.e. the extraction of photons from high-index materials. On the more fundamental side, they lead to the modification of lifetime for sharp transitions (the Purcell effect), recently observed for quantum dots in micropillars, and to strong light-matter coupling for quantum wells embedded in planar microcavities.

scholarly journals Role of dislocations in nitride laser diodes with different indium content

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agata Bojarska-Cieślińska ◽  
Łucja Marona ◽  
Julita Smalc-Koziorowska ◽  
Szymon Grzanka ◽  
Jan Weyher ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Defect Density ◽  
Laser Diodes ◽  
Diffusion Path ◽  
Vapour Phase ◽  
Indium Content ◽  
Nonradiative Recombination ◽  
Light Emitters ◽  
Vapour Phase Epitaxy

AbstractIn this work we investigate the role of threading dislocations in nitride light emitters with different indium composition. We compare the properties of laser diodes grown on the low defect density GaN substrate with their counterparts grown on sapphire substrate in the same epitaxial process. All structures were produced by metalorganic vapour phase epitaxy and emit light in the range 383–477 nm. We observe that intensity of electroluminescence is strong in the whole spectral region for devices grown on GaN, but decreases rapidly for the devices on sapphire and emitting at wavelength shorter than 420 nm. We interpret this behaviour in terms of increasing importance of dislocation related nonradiative recombination for low indium content structures. Our studies show that edge dislocations are the main source of nonradiative recombination. We observe that long wavelength emitting structures are characterized by higher average light intensity in cathodoluminescence and better thermal stability. These findings indicate that diffusion path of carriers in these samples is shorter, limiting the amount of carriers reaching nonradiative recombination centers. According to TEM images only mixed dislocations open into the V-pits, usually above the multi quantum wells thus not influencing directly the emission.

High-efficiency electron-beam-pumped sub-240-nm ultraviolet emitters based on ultra-thin GaN/AlN multiple quantum wells grown by plasma-assisted molecular-beam epitaxy on c-Al2O3

2018 ◽  
Vol 11 (9) ◽  
pp. 091003 ◽  
Author(s):  
Valentin N. Jmerik ◽  
Dmitrii V. Nechaev ◽  
Alexey A. Toropov ◽  
Evgenii A. Evropeitsev ◽  
Vladimir I. Kozlovsky ◽  
...  
Keyword(s):  
Electron Beam ◽  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
High Efficiency ◽  
Multiple Quantum Wells ◽  
Multiple Quantum

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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