Self-organized Si Nanowires with Room-Temperature Photo-Emission

2002 ◽  
Vol 728 ◽  
Author(s):  
Chunhai Ji ◽  
Elena A. Guliants ◽  
Don Abeysinghe ◽  
Wayne A. Anderson
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Lattice Mismatch ◽  
Light Emitting Diode ◽  
Red Light ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Si Nanowires ◽  
Self Organized ◽  
Nickel Disilicide

AbstractTwo-dimensional arrays of self-organized Si nanowires were synthesized using the metal induced growth (MIG) method. In MIG processing, the thermally evaporated 25∼100 nm thick Ni films serve as prelayers for magnetron sputtered Si. When sputtering at 550°C, the Si crystallization occurs via the formation of nickel disilicide followed by subsequent epitaxial growth of Si crystals on nickel disilicide due to an extremely small lattice mismatch. Scanning electron microscopy study showed that the nanowires originated from the Si thin film and grew upwards in bundles. The diameter of the nanowires was 20∼50 nm. The length of the nanowires was typically 1 νm. Transmission electron microscopy and electron diffraction analysis revealed the single crystal structure of nanowires. Quantum-size effects in the produced wires were investigated by measuring the photoluminescence spectra at both low and room temperature. An intense room temperature PL peak centered around 690 nm with FWHM of 180 nm showed the promise of MIG-Si nanowires for red light-emitting diode applications. In addition, self-aligned silicide film on the bottom provides an ultimate back Ohmic contact, which significantly simplifies the fabrication of optoelectronic devices.

Electron Microscopy Study of Submicron Size Antiferromagnetic KMnF3 Nanoparticles and Their Self-assembly

2003 ◽  
Vol 775 ◽  
Author(s):  
Jeffrey Anderson ◽  
Rubi Garcia ◽  
Weilie L. Zhou
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Room Temperature ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Submicron Particles ◽  
Spherical Particles ◽  
Large Area ◽  
Homogeneous Crystal ◽  
Field Emission Electron Microscopy

AbstractSubmicron KMnF3 cubic and spherical nanoparticles were synthesized using the reverse micelle method. The nanostructures of the nanocrystals were studied by field emission electron microscopy and transmission electron microscopy. KMnF3 nanocrystals synthesized at room temperature started with cubic submicron particles (∼100 nm) and consisted of KMnF3 nanocrystallites (10-15 nm). As the reaction continued, the nanocrystals fused together and transformed into perfect cubic nanocrystals. Spherical beads composed of KMnF3 nanocrystallites were observed at low temperature synthesis. As the reaction continued, the spherical particles grew larger, however, no characteristic cubic shape of KMnF3 nanoparticles were observed. Even as they grew larger, there was no evidence of homogeneous crystal morphology as seen in the room temperature samples. Cubic shape KMnF3 nanocrystals were self-assembled into large area self-assembling patterns.

Electron Microscopy Study Of Mocvd-Grown Tio2Thin Films and Tio2/Al203 Interfaces

1990 ◽  
Vol 209 ◽  
Author(s):  
Y. Gao ◽  
K. L. Merkle ◽  
H. L. M. Chang ◽  
T. J. Zhang ◽  
D. J. Lam
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Lattice Mismatch ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Rutile Structure ◽  
Atomic Structures ◽  
Transmission Electron ◽  
Twinning Direction ◽  
Mocvd Technique

ABSTRACTTiO2 thin films grown on (1120) sapphire at 800°C by the MOCVD technique have been characterized by transmission electron microscopy. The TiO2 thin films are single crystalline and have the rutile structure. The epitaxial orientation relationship between the TiO2 thin films (R) and the substrate (S) has been foundto be: (101)[010]R║(1l20)[0001]s. Growth twins in the films are commonly observed with the twin plane{101} and twinning direction <011>. Detailed atomic structures of the twin boundaries and TiO2/α-Al203 interfaces have been investigated by highresolution electron microscopy (HREM).When the interfaces are viewed in the direction of [010]R/[000l]S, the interfaces are found to be structurally coherent in the direction of [1Ol]R/[1100]s,in which the lattice mismatch at the interfaces is about 0.5%.

Electron Microscopy Study of Fatigue Crack Initiation in Ni3Al Single Crystals

1988 ◽  
Vol 133 ◽  
Author(s):  
L. M. Hsiung ◽  
N. S. Stoloff
Keyword(s):  
Electron Microscopy ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
Single Crystals ◽  
Room Temperature ◽  
Fatigue Crack Initiation ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Dislocation Loops ◽  
Defect Clusters

ABSTRACTTransmission electron microscopy of single-slip oriented Ni3Al single crystals cyclically deformed at room temperature revealed a high density of dislocation dipoles and point defect clusters. The majority of the defect clusters were identified by weak-beam TEM to be of vacancy type. The observations of circular perfect dislocation loops, Frank loops, and spherical voids revealed the evidence of vacancy condensation during fatigue cycling at room temperature. Together with SEM observations of surface topography, it is suggested that fatigue crack initiation in Ni3Al single crystals can be rationalized by formation of microvoids at PSB/matrix interfaces.

Transmission electron microscopy study of Ge implanted into SiC

2002 ◽  
Vol 17 (2) ◽  
pp. 479-486 ◽  
Author(s):  
T. Gorelik ◽  
U. Kaiser ◽  
Ch. Schubert ◽  
W. Wesch ◽  
U. Glatzel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Structural Changes ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Means Of Transmission

Hexagonal 6H– and 4H–SiC wafers were implanted with (1−1.5) × 1016 cm−2 germanium ions at room temperature and at 700 °C with subsequent annealing between 1000 and 1600 °C. Structural changes in the SiC matrix were studied in detail by means of transmission electron microscopy (TEM). After implantation at room temperature the hexagonal SiC matrix becomes amorphous and, after annealing, recrystallizes into cubic SiC. The latter process was accompanied by the creation of voids and cracks. In case of high-temperature (700 °C) implantation, where amorphization was avoided, no polytype change in as-implanted and annealed SiC wafers was observed. In annealed samples nanocrystalline precipitates with high Ge content were observed in high-resolution TEM images.

Polarized-light and electron microscopy study of the static domain structure of ferroic Fe3B7O13I boracite at room temperature

2018 ◽  
Vol 534 (1) ◽  
pp. 73-80 ◽  
Author(s):  
A. G. Castellanos-Guzmán ◽  
O. Jiménez ◽  
C. Miramontes-Corona ◽  
D. Mendoza-Anaya ◽  
O. R. Camacho ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Domain Structure ◽  
Room Temperature ◽  
Light And Electron Microscopy ◽  
Polarized Light ◽  
Microscopy Study ◽  
Electron Microscopy Study

Transmission Electron Microscopy Study of CaFe5O7 : Evidence of a Monoclinic Superstructure at Room Temperature

2014 ◽  
Vol 617 ◽  
pp. 237-240 ◽  
Author(s):  
Charlene Delacotte ◽  
Florian Hüe ◽  
Yohann Bréard ◽  
Denis Pelloquin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Complex Structure ◽  
Electron Diffraction Study ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
Monoclinic Cell

An efficient synthesis route is proposed to obtain single powder CaFe5O7ceramic. This complex structure can be described as an intergrowth between one CaFe2O4unit and n= 3 slices of FeO Wustite-type structures. A fine structural study has been carried out at room temperature by transmission electron microscopy (TEM) observations (ED and HREM). The analysis of these data has revealed a supercell with a monoclinic symmetry associated to some twinning phenomena. From thehklconditions deduced to electron diffraction study, the centrosymmetric P21/m setting can be proposed. This monoclinic cell exhibit close relationships with the previous one reported as orthorhombic (ao=3.05 Å, bo= 10.05 Å and co= 18 Å) according to the following metric am=2co, bm=co, cm=bo/2sinβ and β=106.74°.

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