Behavior of Viscous Liquid Byproduct Formed in Exhaust Tube by Silicon Carbide Epitaxial Growth

This study evaluated the chemical behavior of an oily byproduct which was formed in the exhaust tube during the silicon carbide epitaxial growth process using various precursors, such as silanes, chlorosilanes, propane, hydrogen chloride and hydrogen. Most of the precursors were spontaneously emitted from the oily byproduct, when the oily byproduct was kept under a nitrogen gas flow at atmospheric pressure and at room temperature. When the oily byproduct was exposed to 2-5 % chlorine trifluoride gas in ambient nitrogen at room temperature, various gaseous fluorides were produced, accompanying a slight temperature increase.

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150mm Silicon Carbide Selective Embedded Epitaxial Growth Technology by CVD

Materials Science Forum ◽

10.4028/www.scientific.net/msf.897.43 ◽

2017 ◽

Vol 897 ◽

pp. 43-46 ◽

Cited By ~ 5

Author(s):

Kazukuni Hara ◽

Hiroaki Fujibayashi ◽

Yuuichi Takeuchi ◽

Shoichiro Omae

Keyword(s):

Growth Rate ◽

Silicon Carbide ◽

Epitaxial Growth ◽

High Speed ◽

Growth Process ◽

High Growth ◽

High Growth Rate ◽

High Speed Rotation ◽

Speed Rotation ◽

Growth Technology

In this work, we have developed a selective embedded epitaxial growth process on 150-mm-diameter wafer by vertical type hot wall CVD reactor with the aim to realize the all-epitaxial 4H-SiC MOSFETs [1, 2, 3, 4, 5]. We found that at elevated temperature and adding HCl, the epitaxial growth rate at the bottom of trench is greatly enhanced compare to growth on the mesa top. And we obtain high growth rate 7.6μm/h at trench bottom on 150mm-diameter-wafer uniformly with high speed rotation (1000rpm).

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Morphological and Optical Stability in Growth of Fluorescent SiC on Low Off-Axis Substrates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.19 ◽

2013 ◽

Vol 740-742 ◽

pp. 19-22 ◽

Cited By ~ 1

Author(s):

Valdas Jokubavicius ◽

Michl Kaiser ◽

Philip Hens ◽

Peter J. Wellmann ◽

Rickard Liljedahl ◽

...

Keyword(s):

Silicon Carbide ◽

Vapor Phase ◽

Growth Process ◽

Room Temperature ◽

Tantalum Foil ◽

Photoluminescence Intensity ◽

Room Temperature Photoluminescence ◽

Optical Stability ◽

Morphological Instabilities ◽

Sublimation Growth

Fluorescent silicon carbide was grown using the fast sublimation growth process on low off-axis 6H-SiC substrates. In this case, the morphology of the epilayer and the incorporation of dopants are influenced by the Si/C ratio. Differently converted tantalum foils were introduced into the growth cell in order to change vapor phase stochiometry during the growth. Fluorescent SiC grown using fresh and fully converted tantalum foils contained morphological instabilities leading to lower room temperature photoluminescence intensity while an improved morphology and optical stability was achieved with partly converted tantalum foil. This work reflects the importance of considering the use of Ta foil in sublimation epitaxy regarding the morphological and optical stability in fluorescent silicon carbide.

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Modeling of the Mass Transport during Homo-Epitaxial Growth of Silicon Carbide by Fast Sublimation Epitaxy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.52 ◽

2013 ◽

Vol 740-742 ◽

pp. 52-55 ◽

Cited By ~ 4

Author(s):

Thomas Hupfer ◽

Philip Hens ◽

Michl Kaiser ◽

Valdas Jokubavicius ◽

Mikael Syväjärvi ◽

...

Keyword(s):

Silicon Carbide ◽

Theoretical Model ◽

Mass Transport ◽

Epitaxial Growth ◽

Growth Process ◽

Mean Free Path ◽

Inert Gas ◽

Diffusive Growth ◽

The Mean ◽

Sublimation Growth

Ballistic and diffusive growth regimes in the Fast Sublimation Growth Process of silicon carbide can be determined using suggested theoretical model for the mean free path calculations. The influences of temperature and inert gas pressure on the mass transport for the growth of epitaxial layers were analyzed theoretically and experimentally.

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Benzylamine Tartrate as an Organic Glass Substrate for Carbon Films by Evaporation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069417 ◽

1970 ◽

Vol 28 ◽

pp. 484-485

Author(s):

A. C. Faberge

Keyword(s):

Vapor Pressure ◽

Viscous Liquid ◽

Glass Substrate ◽

Room Temperature ◽

Carbon Film ◽

Carbon Films ◽

Organic Glass ◽

Spectroscopic Examination ◽

Polymeric Substrates

Benzylamine tartrate (m.p. 63°C) seems to be a better and more convenient substrate for making carbon films than any of those previously proposed. Using it in the manner described, it is easy consistently to make batches of specimen grids as open as 200 mesh with no broken squares, and without individual handling of the grids. Benzylamine tartrate (hereafter called B.T.) is a viscous liquid when molten, which sets to a glass. Unlike polymeric substrates it does not swell before dissolving; such swelling of the substrate seems to be a principal cause of breakage of carbon film. Mass spectroscopic examination indicates a vapor pressure less than 10−9 Torr at room temperature.

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Intrinsic doping limit and defect-assisted luminescence in Cs4PbBr6

10.26434/chemrxiv.7629467.v3 ◽

2019 ◽

Author(s):

Young-Kwang Jung ◽

Joaquin Calbo ◽

Ji-Sang Park ◽

Lucy D. Wahlley ◽

Sunghyun Kim ◽

...

Keyword(s):

First Principles ◽

Room Temperature ◽

Stokes Shift ◽

Green Luminescence ◽

Counter Ions ◽

Self Consistent ◽

Deep Ultraviolet ◽

Halide Perovskite ◽

Related Compounds ◽

Level Analysis

Cs4PbBr6 is a member of the halide perovskite family that is built from isolated (zero-dimensional) PbBr64- octahedra with Cs+ counter ions. The material exhibits anomalous optoelectronic properties: optical absorption and weak emission in the deep ultraviolet (310 - 375 nm) with efficient luminescence in the green region (~ 540 nm). Several hypotheses have been proposed to explain the giant Stokes shift including: (i) phase impurities; (ii) self-trapped exciton; (iii) defect emission. We explore, using first-principles theory and self-consistent Fermi level analysis, the unusual defect chemistry and physics of Cs4PbBr6. We find a heavily compensated system where the room-temperature carrier concentrations (< 109 cm-3) are more than one million times lower than the defect concentrations. We show that the low-energy Br-on-Cs antisite results in the formation of a polybromide (Br3) species that can exist in a range of charge states. We further demonstrate from excited-state calculations that tribromide moieties are photoresponsive and can contribute to the observed green luminescence. Photoactivity of polyhalide molecules is expected to be present in other halide perovskite-related compounds where they can influence light absorption and emission.

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Intrinsic doping limit and defect-assisted luminescence in Cs4PbBr6

10.26434/chemrxiv.7629467 ◽

2019 ◽

Cited By ~ 1

Author(s):

Young-Kwang Jung ◽

Joaquin Calbo ◽

Ji-Sang Park ◽

Lucy D. Wahlley ◽

Sunghyun Kim ◽

...

Keyword(s):

First Principles ◽

Room Temperature ◽

Stokes Shift ◽

Green Luminescence ◽

Counter Ions ◽

Self Consistent ◽

Deep Ultraviolet ◽

Halide Perovskite ◽

Related Compounds ◽

Level Analysis

Cs4PbBr6 is a member of the halide perovskite family that is built from isolated (zero-dimensional) PbBr64- octahedra with Cs+ counter ions. The material exhibits anomalous optoelectronic properties: optical absorption and weak emission in the deep ultraviolet (310 - 375 nm) with efficient luminescence in the green region (~ 540 nm). Several hypotheses have been proposed to explain the giant Stokes shift including: (i) phase impurities; (ii) self-trapped exciton; (iii) defect emission. We explore, using first-principles theory and self-consistent Fermi level analysis, the unusual defect chemistry and physics of Cs4PbBr6. We find a heavily compensated system where the room-temperature carrier concentrations (< 109 cm-3) are more than one million times lower than the defect concentrations. We show that the low-energy Br-on-Cs antisite results in the formation of a polybromide (Br3) species that can exist in a range of charge states. We further demonstrate from excited-state calculations that tribromide moieties are photoresponsive and can contribute to the observed green luminescence. Photoactivity of polyhalide molecules is expected to be present in other halide perovskite-related compounds where they can influence light absorption and emission.

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High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

Functional Materials Letters ◽

10.1142/s1793604719500322 ◽

2019 ◽

Vol 12 (03) ◽

pp. 1950032 ◽

Cited By ~ 2

Author(s):

Yuchen Deng ◽

Yaming Zhang ◽

Nanlong Zhang ◽

Qiang Zhi ◽

Bo Wang ◽

...

Keyword(s):

Thermal Conductivity ◽

Silicon Carbide ◽

Grain Size ◽

Phase Composition ◽

Room Temperature ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Growth Substrate ◽

Sic Ceramics ◽

Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

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Ag Nanoparticles Sensitized In2O3 Nanograin for the Ultrasensitive HCHO Detection at Room Temperature

Nanoscale Research Letters ◽

10.1186/s11671-019-3213-6 ◽

2019 ◽

Vol 14 (1) ◽

Cited By ~ 6

Author(s):

Shiqiang Zhou ◽

Mingpeng Chen ◽

Qingjie Lu ◽

Yumin Zhang ◽

Jin Zhang ◽

...

Keyword(s):

Indoor Air ◽

Ag Nanoparticles ◽

Room Temperature ◽

Unsolved Problem ◽

Air Pollutant ◽

Ag Nps ◽

Performance Targets ◽

Fabrication Cost ◽

Low Concentrations ◽

Stringent Performance

AbstractFormaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

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