scholarly journals Оптические свойства гибридных гетероструктур GaN/SiC/por-Si/Si(111)

2020 ◽  
Vol 54 (4) ◽  
pp. 346
Author(s):  
П.В. Середин ◽  
Д.Л. Голощапов ◽  
Д.С. Золотухин ◽  
А.С. Леньшин ◽  
А.М. Мизеров ◽  
...  
Keyword(s):  
Optical Quality ◽  
Morphological Properties ◽  
Lower Growth ◽  
Nanoporous Silicon ◽  
Si Substrates ◽  
First Time ◽  
Important Basis ◽  
Gan Film ◽  
Lower Growth Temperature ◽  
Potential Use

Abstract Using a complex of structural and spectroscopic methods of diagnostics, the influence of a nanoporous-silicon ( por -Si) transition layer on the optical properties of GaN layers grown on SiC/ por -Si/ c -Si templates by molecular-beam epitaxy with the plasma activation (MBE PA) of nitrogen is studied. It is shown for the first time that the MBE PA technology of the synthesis of GaN on a virtual SiC/ por -Si/ c -Si substrate provides a means for producing a GaN film of much higher structural and optical quality at a much lower growth temperature compared to those in similar studies, in which growth on porous Si substrates is demonstrated. The use of a por -Si layer makes it possible to improve the structural and morphological properties of the GaN epitaxial layer and to attain unique optical and electrical characteristics of the layer. The data obtained in the study will serve as an important basis for understanding the foundations of the physics of GaN/SiC/ por -Si nanoheterostructures and for promoting their potential use in optoelectronics.

HETERO-GROWTH OF (100) ORIENTATED ZNO FILMS ON SILICON BY SS-CVD

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4250-4254 ◽  
Author(s):  
JIAN-GUO LU ◽  
ZHI-ZHEN YE ◽  
HAN-HONG CHEN ◽  
JING-YUN HUANG ◽  
BING-HUI ZHAO
Keyword(s):  
Texture Coefficient ◽  
Zinc Acetate Dihydrate ◽  
Chemical Vapor ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Lower Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
First Time ◽  
Lower Growth Temperature

ZnO films with (100) preferred orientation are reported for the first time. ZnO films were synthesized on Si(100) substrate by solid-source chemical vapor deposition (SS-CVD) using zinc acetate dihydrate (solid) as a precursor. The structural properties were investigated by X-ray diffraction and atomic force microscopy. Results show that a lower growth temperature and a higher deposition rate will facilitate the formation of (100) texture. The texture coefficient for (100) plane is 3.28.

Effects of Annealing on Structural and Optical Properties of ZnO Nanowires

2014 ◽  
Vol 1675 ◽  
pp. 21-25
Author(s):  
Anas Mazady ◽  
Abdiel Rivera ◽  
Mehdi Anwar
Keyword(s):  
Annealing Temperature ◽  
Defect Density ◽  
Volume Ratio ◽  
Chemical Vapor ◽  
Optical Quality ◽  
Structural And Optical Properties ◽  
Si Substrates ◽  
Higher Temperature ◽  
First Time

ABSTRACTWe report, for the first time, effects of annealing of ZnO NWs grown on p-Si substrates. ZnO NWs are grown using metalorganic chemical vapor deposition (MOCVD) and thermal annealing was performed in situ under nitrogen ambient at different stages of the growth process. Increasing the annealing temperature of the ZnO seed epi-layer from 635 °C to 800 °C does not affect the morphology of the grown NWs. In contrast, annealing the NWs themselves at 800 °C results in a 48% decrease of the surface area to volume ratio of the grown NWs. The optical quality can be improved by annealing the seed layer at a higher temperature of 800 °C, although annealing the NWs themselves does not affect the defect density.

Rapid Epitaxial Growth of Si and SiGe Mono-Crystalline Films on Silicon-on-Glass Substrates by Reactive CVD Using SiH4, GeH4, and F2

2012 ◽  
Vol 1426 ◽  
pp. 331-337
Author(s):  
Hiroshi Noge ◽  
Akira Okada ◽  
Ta-Ko Chuang ◽  
J. Greg Couillard ◽  
Michio Kondo
Keyword(s):  
Epitaxial Growth ◽  
Heating Temperature ◽  
Exothermic Reaction ◽  
Epitaxial Films ◽  
Si Substrates ◽  
Glass Substrates ◽  
Good Crystallinity ◽  
Crystalline Films ◽  
Si Films ◽  
First Time

ABSTRACTWe have succeeded in the rapid epitaxial growth of Si, Ge, and SiGe films on Si substrates below 670 ºC by reactive CVD utilizing the spontaneous exothermic reaction between SiH4, GeH4, and F2. Mono-crystalline SiGe epitaxial films with Ge composition ranging from 0.1 to 1.0 have been successfully grown by reactive CVD for the first time.This technique has also been successfully applied to the growth of these films on silicon-on-glass substrates by a 20 - 50 ºC increase of the heating temperature. Over 10 μm thick epitaxial films at 3 nm/s growth rate are obtained. The etch pit density of the 5.2 μm-thick Si0.5Ge0.5 film is as low as 5 x 106 cm-2 on top. Mobilities of the undoped SiGe and Si films are 180 to 550 cm2/Vs, confirming the good crystallinity of the epitaxial films.

Monolithic Integration of Si and GaAs Devices

1986 ◽  
Vol 67 ◽  
Author(s):  
H. K. Choi ◽  
G. W. Turner ◽  
B-Y. Tsaur ◽  
T. H. Windhorn
Keyword(s):  
Monolithic Integration ◽  
Double Heterostructure ◽  
Si Substrates ◽  
Gaas Substrates ◽  
Gaas Devices ◽  
Voltage Pulses ◽  
First Time

ABSTRACTIntegration of Si MOSFETs with GaAs MESFETs and with GaAs/AlGaAs double-heterostructure LEDs on monolithic GaAs/Si substrates is reported. Both Si MOSFETs and GaAs MESFETs show characteristics comparable to those for devices fabricated on separate Si and GaAs substrates. In LED/MOSFET integration, the cathode of each LED is connected with the drain of a MOSFET. This is the first time that Si and GaAs devices have been monolithically interconnected. LED modulation rates up to 27 Mbps have been achieved by applying a stream of voltage pulses to the MOSFET gate.

A DFT study of RuO4 interactions with porous materials: metal–organic frameworks (MOFs) and zeolites

2018 ◽  
Vol 20 (24) ◽  
pp. 16770-16776 ◽  
Author(s):  
Siwar Chibani ◽  
Michael Badawi ◽  
Thierry Loiseau ◽  
Christophe Volkringer ◽  
Laurent Cantrel ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Porous Materials ◽  
Metal Organic Frameworks ◽  
Dft Study ◽  
Hydrated Form ◽  
Metal Organic ◽  
First Time ◽  
Potential Use ◽  
Multiple Hydrogen Bonds

The potential use of zeolite and MOF materials for the capture of RuO4 has been investigated for the first time. A hydrated form of HKUST-1 could be a promising sorbent due to its ability to form multiple hydrogen bonds.

scholarly journals Exploring the Effect of the Irradiation Time on Photosensitized Dendrimer-Based Nanoaggregates for Potential Applications in Light-Driven Water Photoreduction

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1316 ◽  
Author(s):  
Martínez ◽  
Inostroza-Rivera ◽  
Durán ◽  
Molero ◽  
Bonardd ◽  
...  
Keyword(s):  
Active Sites ◽  
Methyl Viologen ◽  
Irradiation Time ◽  
Pt Nanoparticles ◽  
Morphological Properties ◽  
Fourth Generation ◽  
Self Assembling ◽  
Potential Applications ◽  
Potential Use

Fourth generation polyamidoamine dendrimer (PAMAM, G4) modified with fluorescein units (F) at the periphery and Pt nanoparticles stabilized by L-ascorbate were prepared. These dendrimers modified with hydrophobic fluorescein were used to achieve self-assembling structures, giving rise to the formation of nanoaggregates in water. The photoactive fluorescein units were mainly used as photosensitizer units in the process of the catalytic photoreduction of water propitiated by light. Complementarily, Pt-ascorbate nanoparticles acted as the active sites to generate H2. Importantly, the study of the functional, optical, surface potential and morphological properties of the photosensitized dendrimer aggregates at different irradiation times allowed for insights to be gained into the behavior of these systems. Thus, the resultant photosensitized PAMAM-fluorescein (G4-F) nanoaggregates (NG) were conveniently applied to light-driven water photoreduction along with sodium L-ascorbate and methyl viologen as the sacrificial reagent and electron relay agent, respectively. Notably, these aggregates exhibited appropriate stability and catalytic activity over time for hydrogen production. Additionally, in order to propose a potential use of these types of systems, the in situ generated H2 was able to reduce a certain amount of methylene blue (MB). Finally, theoretical electronic analyses provided insights into the possible excited states of the fluorescein molecules that could intervene in the global mechanism of H2 generation.

Formation of Sub-100 NM GE Wires on Si by E-Beam Evaporation/Lithography

1995 ◽  
Vol 380 ◽  
Author(s):  
C. Deng ◽  
J. C. Wu ◽  
C. J. Barbero ◽  
T. W. Sigmon ◽  
M. N. Wybourne
Keyword(s):  
Cross Section ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Si Substrates ◽  
Novel Technique ◽  
Atomic Force ◽  
Transmission Electron ◽  
First Time ◽  
Scanning Electron

ABSTRACTA fabrication process for sub-100 nm Ge wires on Si substrates is reported for the first time. Wires with a cross section of 6 × 57 nm2 are demonstrated. The wire structures are analyzed by atomic force (AFM), scanning electron (SEM), and transmission electron microscopy (TEM). Sample preparation for TEM is performed using a novel technique using both pre and in situ deposition of multiple protection layers using a Focused Ion Beam (FIB) micromachining system.

Complete Field Guide to Dragonflies of Australia

2006 ◽  
Author(s):  
Gunther Theischinger ◽  
John Hawking
Keyword(s):  
Environmental Protection ◽  
Freshwater Fish ◽  
Well Being ◽  
Detailed Knowledge ◽  
Field Guide ◽  
Distribution Maps ◽  
Identification Keys ◽  
Complete Field ◽  
First Time ◽  
Important Basis

Dragonflies and damselflies are conspicuous insects – many are large and brightly coloured. Here for the first time is a comprehensive guide to the Australian dragonfly fauna. The book includes identification keys not only for adults but also for their larvae, commonly known as ‘mud eyes’ and often used as bait for freshwater fish. With stunning full-colour images and distribution maps, the book covers all 30 families, 110 genera and 324 species found in Australia. Dragonflies are valuable indicators of environmental well-being. A detailed knowledge of the dragonfly fauna and its changes is therefore an important basis for decisions about environmental protection and management. Their extraordinary diversity will interest entomologists and amateur naturalists alike.

scholarly journals Optical quality ZnSe films and low loss waveguides on Si substrates for mid-infrared applications

2017 ◽  
Vol 7 (3) ◽  
pp. 712 ◽  
Author(s):  
Vinita Mittal ◽  
Neil P. Sessions ◽  
James S. Wilkinson ◽  
Ganapathy Senthil Murugan
Keyword(s):  
Optical Quality ◽  
Low Loss ◽  
Mid Infrared ◽  
Si Substrates

ArF Excimer Laser-Induced Epitaxial Growth of GaAs Films on Si

1988 ◽  
Vol 116 ◽  
Author(s):  
Shirley S. Chu ◽  
T. L. Cpu ◽  
C. L. Chang
Keyword(s):  
Gallium Arsenide ◽  
Substrate Temperature ◽  
Excimer Laser ◽  
Substrate Surface ◽  
Molar Ratio ◽  
Structural Perfection ◽  
Lower Growth ◽  
Si Substrates ◽  
Gaas Films ◽  
Arf Excimer Laser

AbstractEpitaxial gallium arsenide films have been deposited on single crystalline GaAs substrates of {100} orientation and Si substrates of 3° off the {100} orientation by ArF excimer laser-induced metalorganic chemical vapor deposition. The important process parameters include the cleanliness of the substrate surface, substrate temperature, the composition, flow rate, and pressure of the reaction mixture, and the pulse energy and pulse rate of the laser. Particular attention was directed to the in-situ cleaning of the substrate surface prior to the deposition process. Homoepitaxial gallium arsenide films of good structural perfection have been deposited at 425°- 500 ° C and their single crystallinity has been confirmed by transmission electron microscopy. The carrier concentration decreases with increasing AsH3/(CH3)3 Ga molar ratio and with decreasing substrate temperature. Lower growth rate during the initial stage of deposition is necessary to obtain heteroepitaxial gallium arsenide films on Si with good structural perfection. The TEM examination of GaAs films of 0.15–0.2 µm thickness deposited on Si substrates at 500 °C has shown that stacking faults were present in the GaAs films; however, there is no apparent threading dislocations in the surface region of the thin GaAs film.

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