Optical Properties of Light-Hole Excitons in MOVPE Grown (Ga,In)As-GaAs Quantum Wells

1994 ◽  
Vol 340 ◽  
Author(s):  
P. Bigenwald ◽  
O. Laire ◽  
X. Zhang ◽  
O. Briot ◽  
B. Gil ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Growth Parameters ◽  
Vapour Phase ◽  
Light Hole ◽  
Type I ◽  
Vapour Phase Epitaxy ◽  
Novel Approach ◽  
Reflectivity Spectra ◽  
Metalorganic Vapour Phase Epitaxy

ABSTRACTWe study the optical properties of metalorganic vapour phase epitaxy (MOVPE) grown (Ga,In)As-GaAs single quantum wells as a function of the growth parameters. Our objective is to study the properties of the type II light-hole excitons with light-hole wave function delocalized in the thick GaAs layers and electrons confined in the ternary alloy. However, marked structures (like for type I excitons) are observed in the reflectivity spectra. This we interpret in the context of a novel approach of the exciton problem via a self-consistent calculation of the electron-hole interaction.

Characterization of GaAs/AlGaAs quantum wells and quantum wires by chemical lattice imaging

1994 ◽  
Vol 52 ◽  
pp. 736-737
Author(s):  
A. Carlsson ◽  
J.-O. Malm ◽  
A. Gustafsson
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Vapour Phase ◽  
Quantitative Information ◽  
Lattice Imaging ◽  
Vapour Phase Epitaxy ◽  
Metalorganic Vapour Phase Epitaxy ◽  
High Resolution Images

In this study a quantum well/quantum wire (QW/QWR) structure grown on a grating of V-grooves has been characterized by a technique related to chemical lattice imaging. This technique makes it possible to extract quantitative information from high resolution images.The QW/QWR structure was grown on a GaAs substrate patterned with a grating of V-grooves. The growth rate was approximately three monolayers per second without growth interruption at the interfaces. On this substrate a barrier of nominally Al0.35 Ga0.65 As was deposited to a thickness of approximately 300 nm using metalorganic vapour phase epitaxy . On top of the Al0.35Ga0.65As barrier a 3.5 nm GaAs quantum well was deposited and to conclude the structure an additional approximate 300 nm Al0.35Ga0.65 As was deposited. The GaAs QW deposited in this manner turns out to be significantly thicker at the bottom of the grooves giving a QWR running along the grooves. During the growth of the barriers an approximately 30 nm wide Ga-rich region is formed at the bottom of the grooves giving a Ga-rich stripe extending from the bottom of each groove to the surface.

scholarly journals Towards practical applications of quantum emitters in boron nitride

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Koperski ◽  
K. Pakuła ◽  
K. Nogajewski ◽  
A. K. Dąbrowska ◽  
M. Tokarczyk ◽  
...  
Keyword(s):  
Optical Properties ◽  
Boron Nitride ◽  
Vapour Phase ◽  
Emission Characteristics ◽  
Vapour Phase Epitaxy ◽  
Practical Applications ◽  
Metalorganic Vapour Phase Epitaxy ◽  
Polydimethylsiloxane Films ◽  
Background Luminescence ◽  
Quantum Emitters

AbstractWe demonstrate quantum emission capabilities from boron nitride structures which are relevant for practical applications and can be seamlessly integrated into a variety of heterostructures and devices. First, the optical properties of polycrystalline BN films grown by metalorganic vapour-phase epitaxy are inspected. We observe that these specimens display an antibunching in the second-order correlation functions, if the broadband background luminescence is properly controlled. Furthermore, the feasibility to use flexible and transparent substrates to support hBN crystals that host quantum emitters is explored. We characterise hBN powders deposited onto polydimethylsiloxane films, which display quantum emission characteristics in ambient environmental conditions.

scholarly journals Tuning the Size, Shape and Density of γ′-GayFe4−yN Nanocrystals Embedded in GaN

Crystals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 50 ◽  
Author(s):  
Andrea Navarro-Quezada ◽  
Thibaut Devillers ◽  
Tian Li ◽  
Alberta Bonanni
Keyword(s):  
Growth Parameters ◽  
Vapour Phase ◽  
Spatial Density ◽  
Magnetic Response ◽  
Vapour Phase Epitaxy ◽  
Size And Shape ◽  
On Demand ◽  
Metalorganic Vapour Phase Epitaxy ◽  
Self Assembled ◽  
Magnetic Nanocrystal

Phase-separated semiconductor systems hosting magnetic nanocrystal (NCs) are attracting increasing attention, due to their potential as spintronic elements for the next generation of devices. Owing to their morphology- and stoichiometry-dependent magnetic response, self-assembled γ ’-Ga y Fe 4 − y N NCs embedded in a Fe δ -doped GaN matrix, are particularly versatile. It is studied and reported here, how the tuning of relevant growth parameters during the metalorganic vapour phase epitaxy process affects the crystalline arrangement, size, and shape of these self-assembled nanostructures. In particular, it is found that the Ga-flow provided during the δ -doping, determines the amount of Fe incorporated into the layers and the spatial density of the NCs. Moreover, the in-plane dimensions of the NCs can also be controlled via the Ga-flow, conditioning the aspect-ratio of the embedded nanostructures. These findings are pivotal for the design of nanocrystal arrays with on-demand size and shape, essential requirements for the implementation into functional devices.

Strain Induced Compositional Modulations in AlGaAs Overlayers Induced by Lateral Surface Gratings

2000 ◽  
Vol 618 ◽  
Author(s):  
U. Pietsch ◽  
U. Zeimer ◽  
L. Hofmann ◽  
J. Grenzer ◽  
S. Gramlich
Keyword(s):  
Quantum Wells ◽  
Grazing Incidence ◽  
Vapour Phase ◽  
High Index ◽  
Lateral Strain ◽  
Vapour Phase Epitaxy ◽  
Al Content ◽  
Compositional Modulation ◽  
Surface Grating ◽  
Metalorganic Vapour Phase Epitaxy

ABSTRACTStrain and compositional modulation in AlxGa1−xAs layers grown by metalorganic vapour phase epitaxy (MOVPE) over a sinusoidally shaped GaAs (001) surface grating were studied by scanning electron microscopy (SEM), X-ray grazing-incidence diffraction (GID) and photoluminescence (PL). Two growth temperatures and two compositions were chosen to realize planar overlayers. By SEM a periodic reduction in Al-content was found at the valley positions of the GaAs grating. The appearance of such vertical quantum wells (VQWs) has been explained by the growth rate anisotropy between high-index and (001) planes and a curvature-induced capillarity flow of Ga. Estimated from PL energies a larger reduction of the Al-concentration in the VQW and also at the high-index sidewall facets was found than compared to predictions from the capillarity flow theory. Using depth-resolved GID we show that the formation of VQWs is accompanied by a periodic lateral strain field. Therefore we assume, that the formation of the VQWs is influenced by strain induced diffusion due to the interaction of opposite sidewall facets.

scholarly journals Электролюминесценция одиночных InGaN/GaN микропирамид

2019 ◽  
Vol 126 (2) ◽  
pp. 180
Author(s):  
А.В. Бабичев ◽  
Д.В. Денисов ◽  
P. Lavenus ◽  
G. Jacopin ◽  
M. Tchernycheva ◽  
...  
Keyword(s):  
Optical Properties ◽  
Light Emission ◽  
Vapour Phase ◽  
Emission Sources ◽  
Light Sources ◽  
Vapour Phase Epitaxy ◽  
Light Emitting ◽  
Metalorganic Vapour Phase Epitaxy ◽  
Point Light ◽  
Biosensor Applications

AbstractThe results of the fabrication of technological regimes of formation and the study of the optical properties of light emitting diodes (LED) micropyramids based on InGaN/GaN are presented. The structures were formed by the method of Metalorganic vapour-phase epitaxy. LED hetero structures based on single micropyramids demonstrate electroluminescence at a wavelength of 520–590 nm, which is shifted to the shortwave length region with increasing current pumping. These light-emission sources are of interest for the fabrication of high-intensity point light sources for biosensor applications.

Sign in / Sign up

Export Citation Format

Share Document