Liquid Phase Electroepitaxial (LPEE) Growth of GaSb and GaInAsSb

1989 ◽  
Vol 160 ◽  
Author(s):  
Shanthi N. Iyer ◽  
Ali Abul-Fadl ◽  
Albert T. Macrander ◽  
Jonathan H.Lewis ◽  
Ward J. Collis ◽  
...  
Keyword(s):  
Growth Rate ◽  
Liquid Phase ◽  
Current Density ◽  
Room Temperature ◽  
Composition Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
A Current

AbstractLiquid phase electroepitaxial technique has been used for the growth of GaSb and GalnAsSb in the composition range corresponding to peak band gap wavelengths of 1.7-2.28μm. The growth rate of these layers were examined as a function of current density. The growth rates of these layers are typically 0.8μm/min. at a current density of 10A/cm2. The quality of the layers was evaluated by x-ray diffraction and room temperature photoluminescence.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

Growth mechanism and characterization of ZnO nano-tubes synthesized using the hydrothermal-etching method

2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Yan Li ◽  
Chuan-Sheng Liu ◽  
Yun-Ling Zou
Keyword(s):  
Room Temperature ◽  
Morphological Analysis ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Etching Method ◽  
Nano Rods ◽  
Two Stages

AbstractZnO nano-tubes (ZNTs) have been successfully synthesized via a simple hydrothermal-etching method, and characterized by X-ray diffraction, field emission scanning electron microscopy and room temperature photoluminescence measurement. The as-synthesized ZNTs have a diameter of 500 nm, wall thickness of 20–30 nm, and length of 5 µm. Intensity of the plane (0002) diffraction peak, compared with that of plane (10$$ \bar 1 $$0) of ZNTs, is obviously lower than that of ZnO nano-rods. This phenomenon can be caused by the smaller cross section of plane (0002) of the nano-tubes compared with that of other morphologies. On basis of the morphological analysis, the formation process of nano-tubes can be proposed in two stages: hydrothermal growth and reaction etching process.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

Structure of CoxAg100-x and Its Relation to GMR

1992 ◽  
Vol 286 ◽  
Author(s):  
John Q. Xiao ◽  
J. Samuel ◽  
C. L. Chien
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Composition Range ◽  
Magnetic Scattering ◽  
Granular System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Concentration

ABSTRACTWe have studied the structure of the Co-Ag granular system across the entire composition range, as well as the annealed samples, using transmission electron microscopy (TEM) and x-ray diffraction. GMR, as much as 80% at 5K and 25% at room temperature, have been observed. The absolute values of the resistivity (ρ) and the change of the resistivity (δρ) as functions of the magnetic Co concentration and the annealing temperature have been determined. A linear relation between δρ and I/rco, where rco is Co particle size, has been found. This result suggests that the magnetic scattering at the interfaces is crucial to GMR.

Phosphorus Passivation of GaAs

1998 ◽  
Vol 510 ◽  
Author(s):  
S.P. Watkins ◽  
X. Xu ◽  
J. Hu ◽  
R. Ares ◽  
P. Yeo ◽  
...  
Keyword(s):  
Room Temperature ◽  
Thin Layers ◽  
Difference Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Reflectance Difference Spectroscopy ◽  
Similar Chemical ◽  
Pl Intensity ◽  
Undoped Gaas

AbstractWe have performed a systematic study of the effect of various phosphorus passivation techniques on the room temperature photoluminescence (PL) intensity of undoped GaAs. The effects of passivation by two methods are compared: (1) the P-exchange reaction on exposure to tertiarybutylphosphine (TBP) vapour between 500-620°C, and (2) the growth of thin layers of GaP directly on GaAs. An x-ray diffraction technique was used to estimate the thickness of the passivating layers. Reflectance difference spectroscopy indicated a similar chemical origin for the two passivation methods. Both passivation techniques resulted in strong enhancements in the room temperature PL. PL intensity was observed to increase very rapidly with adsorbed P for both cases saturating at approximately 2 monolayers equivalent GaP coverage.

PREPARATION OF LUMINESCENT PbWO4 MICROCRYSTALS WITH HIERARCHICAL STRUCTURES BY USING MICROWAVE IRRADIATION HEATING METHOD

2010 ◽  
Vol 24 (32) ◽  
pp. 3081-3087 ◽  
Author(s):  
GENGPING WAN ◽  
GUIZHEN WANG
Keyword(s):  
Electron Microscopy ◽  
Microwave Irradiation ◽  
Room Temperature ◽  
Hierarchical Structures ◽  
X Ray Diffraction ◽  
Lead Tungstate ◽  
Heating Method ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Scanning Electron

Lead tungstate ( PbWO 4) microcrystals with hierarchical structures have been successfully synthesized via a facile microwave irradiation heating method. The cetyltrimethylammonium bromine (CTAB) and microwave-heated power were found to play an important role in the morphological control of resulting PbWO 4 mirocrystals. The products were characterized by the techniques of powder X-ray diffraction and field-emission scanning electron microscopy. A growth mechanism of PbWO 4 microstructures was proposed. The luminescence properties of the final products were investigated and the as-prepared PbWO 4 microcrystals displayed a very unique room-temperature photoluminescence compared to the reported results.

EFFECT OF VANADIUM CONTENT ON PHOTOLUMINESCENCE AND MAGNETIC PROPERTIES OF DOPED ZnO THIN FILMS

2010 ◽  
Vol 24 (10) ◽  
pp. 945-951 ◽  
Author(s):  
LIWEI WANG ◽  
ZHENG XU ◽  
SULING ZHAO ◽  
LIFANG LU ◽  
FUJUN ZHANG
Keyword(s):  
Photoluminescence Spectrum ◽  
Room Temperature ◽  
Doping Concentration ◽  
Vanadium Content ◽  
X Ray Diffraction ◽  
Vanadium Concentration ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Room Temperature Photoluminescence Spectrum ◽  
Diffraction Patterns

ZnO : V thin films with different doping concentration (0%, 1.8%, 3.9%, 6.8%, 10%, and 13%) were fabricated by direct current magnetron sputtering. The X-ray diffraction patterns show that the wurzite structure changed with doping concentration. Furthermore, we could not find any vanadium cluster or phase separation in the X-ray diffraction patterns. The photoluminescence of ZnO : V with different vanadium concentration was investigated. The room temperature photoluminescence spectrum indicates that the films have purple band with 370 nm and the bands with 475 and 490 nm. The peak intensity of room temperature photoluminescence spectrum was affected by vanadium contents and its position remained stable. The intensity of band with 370 nm increases with raising the vanadium concentration and then decreases. The hysteresis behavior indicates that films were ferromagnetic at 50 K. Room temperature ferromagnetism was observed for the film with the doping concentration at 6.8%. However, in this case almost no hysteresis is noticeable. The results implied that the doping concentration and crystalline microstructure influence strongly the film's magnetic characteristics. Increasing the vanadium content in the film caused the degradation of the magnetic ordering.

Mn, Cu Doping and Optical Properties of Highly Crystalline Ultralong ZnS Nanowires

2007 ◽  
Vol 31 ◽  
pp. 114-116 ◽  
Author(s):  
N.D. Chien ◽  
H.V. Chung ◽  
P.T. Huy ◽  
Do Jin Kim ◽  
Maurizio Ferrari
Keyword(s):  
Room Temperature ◽  
Doping Concentration ◽  
Thermal Evaporation ◽  
X Ray Diffraction ◽  
Cu Doping ◽  
Mn Doping ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Single Crystal Structures ◽  
Scanning Electron

Manganese (Mn) and copper (Cu) doping of ZnS nanowires was achieved by thermal evaporation of Mn, Cu doped ZnS nanopowders. Field emission scanning electron microscopy, and X-ray diffraction studies of the obtained ZnS nanowires demonstrate that the nanowires are single crystal structures and have diameters about 30-200 nm and lengths up to 1 millimeter. Room temperature photoluminescence (PL) measurements show a common PL peak around 520 nm for all ZnS nanowires samples, while impurity-related emission band are observed in doped ZnS nanowires. The dependence of the PL intensity on Mn doping concentration has also been investigated. It is shown that for high Mn doping concentration (10%) in the starting ZnS nanopowders, new emission bands (orange-red and red bands) are observed from the ZnS:Mn nanowires products. The origins of these new emission bands are discussed and brought up for further discussion.

Photoluminescence and Structural Characteristics of SnO2 Nanopetals Synthesized by Thermal Evaporation

2010 ◽  
Vol 152-153 ◽  
pp. 697-701
Author(s):  
Bing Wang ◽  
Ling Li
Keyword(s):  
Room Temperature ◽  
Thermal Evaporation ◽  
Structural Characteristics ◽  
The Self ◽  
Silicon Substrates ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Sno2 Nanostructure

A new nanostructure, (2D) nanopetal of SnO2, has been grown on single silicon substrates by Au-Ag alloying catalyst assisted carbothermal evaporation of SnO2. Field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD) and Raman are employed to identify the morphology and structure of the synthesized productions. Room-temperature photoluminescence (PL) is used to characterize the luminescence of SnO2 nanostructure. Three new peaks at 356, 450 and 489 nm in the measured photoluminescence spectra are observed, implying that more luminescence centers exist in SnO2 nanopetals due to nanocrystals and defects. The growth of the SnO2 nanopetals is discussed on the basis of the self-catalyst mechanism.

MBE GROWN ZnSSe/ZnMgSSe MQW STRUCTURE FOR BLUE VCSEL

2007 ◽  
Vol 06 (05) ◽  
pp. 407-410 ◽  
Author(s):  
I. P. KAZAKOV ◽  
V. I. KOZLOVSKY ◽  
V. P. MARTOVITSKY ◽  
YA. K. SKASYRSKY ◽  
M. D. TIBERI ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Optical Scanning ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Two Phases

ZnSSe / ZnMgSSe MQW structures were grown by molecular beam epitaxy on GaAs substrates. The band gap of ZnMgSSe barriers was approximately 3 eV at room temperature. Cathodoluminescence, X-ray diffraction, optical, scanning electron beam, and atomic force microscopy were all used for structure characterization. Decay of the ZnMgSSe solid solution in at least two phases was observed. Improvement in the quality of the crystal lattice and surface morphology was achieved by mismatching the ZnMgSSe from the GaAs substrate by increasing the lattice period by 0.24%.

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