scholarly journals Site-controlled growth of GaN nanorods with inserted InGaN quantum wells on mu-cone patterned sapphire substrates by plasma-assisted MBE

2018 ◽  
Vol 52 (5) ◽  
pp. 526
Author(s):  
V.N. Jmerik ◽  
T.V. Shubina ◽  
D.V. Nechaev ◽  
A.N. Semenov ◽  
D.A. Kirilenko ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Layer Growth ◽  
Regular Array ◽  
Nucleation Layer ◽  
New Approach ◽  
Sapphire Substrates ◽  
Regular Arrays ◽  
Ingan Quantum Wells ◽  
Patterned Sapphire Substrates

AbstractWe report on a new approach to fabricate regular arrays of GaN nanorods (NRs) with InGaN QWs by plasma-assisted molecular-beam epitaxy (PA MBE) on micro-cone patterned sapphire substrates (μ-CPSSs). A two-stage PA MBE fabrication process of GaN NRs has been developed, starting with a high temperature nucleation layer growth at metal-rich conditions to aggregate selectively GaN nucleus on c-oriented areas of the μ-CPSSs and followed by growth of 1-μm-thick GaN NRs at strongly nitrogen-rich conditions exactly on the cone tips. These results are explained by energetically favorable GaN growth on the (000-) oriented sapphire surface. Both micro-photoluminescence and micro-cathodoluminescence confirm the formation of regular array of optically and spectrally isolated NRs without usage of any nanolithography.

Site-Controlled Growth of GaN Nanorods with Inserted InGaN Quantum Wells on μ-Cone Patterned Sapphire Substrates by Plasma-Assisted MBE

2018 ◽  
Vol 52 (5) ◽  
pp. 667-670 ◽  
Author(s):  
V. N. Jmerik ◽  
T. V. Shubina ◽  
D. V. Nechaev ◽  
A. N. Semenov ◽  
D. A. Kirilenko ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Controlled Growth ◽  
Sapphire Substrates ◽  
Ingan Quantum Wells ◽  
Patterned Sapphire Substrates

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

Optical and Structural Properties of AlGaN/GaN Quantum Wells Grown by Molecular Beam Epitaxy

1998 ◽  
Vol 537 ◽  
Author(s):  
Nicolas Grandjean ◽  
Jean Massies ◽  
Mathieu Leroux ◽  
Marguerite Latigt ◽  
Pierre Lefebvre ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Stark Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantum Confined Stark Effect ◽  
Sapphire Substrates ◽  
Gan Buffer Layer ◽  
Large Quantum

AbstractAIGaN/GaN quantum well (QWs) were grown on (0001) sapphire substrates by molecular beam epitaxy (MBE) using ammonia as nitrogen precursor. The Al composition in the barriers was varied between 8 and 27 % and the well thickness from 4 to 17 monolayers (MLs, 1ML = 2.59Å). X-ray diffraction (XRD) experiments are used to investigate the strain state of both the well and the barriers. The QW transition energy are measured by low temperature photoluminescence (PL). A large quantum confined Stark effect is observed leading to QW luminescence much lower than the emission line of the GaN buffer layer for well width above a certain critical thickness. The built-in electric field responsible for such a phenomenon is deduced from fit of the PL data. Its magnitude is of several hundred kV/cm and increases linearly with the Al composition.

Realization of high efficiency AlGaN-based multiple quantum wells grown on nano-patterned sapphire substrates

CrystEngComm ◽  
2020 ◽  
Author(s):  
Yuanhao Sun ◽  
Fujun Xu ◽  
Na Zhang ◽  
Jing Lang ◽  
Jiaming Wang ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Quantum Wells ◽  
High Efficiency ◽  
Growth Conditions ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

Growth of AlGaN-based multiple quantum wells (MQWs) has been attempted on nano-patterned sapphire substrates (NPSSs). By adopting a critical-temperature approach and optimizing the growth conditions of V/III ratio and Si...

V-Defect and Dislocation Analysis in InGaN Multiple Quantum Wells on Patterned Sapphire Substrate

2018 ◽  
Vol 787 ◽  
pp. 37-41
Author(s):  
Huan You Wang ◽  
Qiao Lai Tan ◽  
Gui Jin
Keyword(s):  
Quantum Wells ◽  
Strain Relaxation ◽  
Chemical Vapor ◽  
Multiple Quantum ◽  
Cross Sectional ◽  
Patterned Sapphire Substrate ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Multi Quantum Well ◽  
Patterned Sapphire Substrates

InGaN/GaN multiquantum well (MQW) structures have been grown on cone-shaped patterned sapphire substrates (CPSS) by metalorganic chemical vapor deposition (MOCVD). From the transmission electron microscopy (TEM) results, we found that most of the threading dislocations (TDs) in the trench region of the CPSS were bent by lateral growth mode. Also the staircase-like TDs were observed near the slant region of the cone pattern, they converged at the slope of the cone patterned region by staircase-upward propagation, which seems to effectively prevent TDs from vertical propagation in the trench region. The associated dislocation runs up into the overgrown GaN layer and MQW, and some (a+c) dislocations were shown to decompose inside the multi-quantum well, giving rise to a misfit segment in the c-plane and a V-shape defect. From cross-sectional TEM, we found that all V defects are not always connected with TDs at their bottom, some V defects are generated from the stacking mismatch boundaries induced by stacking faults which are formed within the MQW due to the strain relaxation.

scholarly journals Optical and Structural Properties of AlGaN/GaN Quantum Wells Grown by Molecular Beam Epitaxy

1999 ◽  
Vol 4 (S1) ◽  
pp. 962-967
Author(s):  
Nicolas Grandjean ◽  
Jean Massies ◽  
Mathieu Leroux ◽  
Marguerite Laügt ◽  
Pierre Lefebvre ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Stark Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantum Confined Stark Effect ◽  
Sapphire Substrates ◽  
Gan Buffer Layer ◽  
Large Quantum

AlGaN/GaN quantum well (QWs) were grown on (0001) sapphire substrates by molecular beam epitaxy (MBE) using ammonia as nitrogen precursor. The Al composition in the barriers was varied between 8 and 27 % and the well thickness from 4 to 17 monolayers (MLs, 1ML = 2.59Å). X-ray diffraction (XRD) experiments are used to investigate the strain state of both the well and the barriers. The QW transition energy are measured by low temperature photoluminescence (PL). A large quantum confined Stark effect is observed leading to QW luminescence much lower than the emission line of the GaN buffer layer for well width above a certain critical thickness. The built-in electric field responsible for such a phenomenon is deduced from fit of the PL data. Its magnitude is of several hundred kV/cm and increases linearly with the Al composition.

Indium distribution inside quantum wells: The effect of growth interruption in MBE

2002 ◽  
Vol 743 ◽  
Author(s):  
A. M. Sanchez ◽  
P. Ruterana ◽  
S. Kret ◽  
P. Dłużewski ◽  
G. Maciejewski ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Strain Distribution ◽  
Metalorganic Chemical Vapor Deposition ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Layer Growth ◽  
Growth Interruption ◽  
Resolution Electron ◽  
Microscopy Image

ABSTRACTQuantitative analysis of high resolution electron microscopy image has been carried out to measure the indium distribution inside InGaN/GaN quantum well. The analyzed samples were nominally grown with 15% indium composition by molecular beam epitaxy with interruptions during the InxGa1-xN layer growth. The strain distribution is not homogeneous inside the quantum wells, and indium rich clusters can be observed. Areas with almost no indium concentration were observed corresponding to the growth interruption. A comparison with samples grown by metalorganic chemical vapor deposition is attempted.

Photoluminescence characterization of InGaN/InGaN quantum wells grown by plasma-assisted molecular beam epitaxy: Impact of nitrogen and galium fluxes

2015 ◽  
Vol 252 (5) ◽  
pp. 983-988 ◽  
Author(s):  
Michał Baranowski ◽  
Robert Kudrawiec ◽  
Jan Misiewicz ◽  
Henryk Turski ◽  
Czesław Skierbiszewski
Keyword(s):  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Ingan Quantum Wells
Sign in / Sign up

Export Citation Format

Share Document