Study of band structure InxGa1−xN∕GaN multiple quantum wells by high-resolution electron microscopy and electron holography

2005 ◽  
Vol 86 (4) ◽  
pp. 041902 ◽  
Author(s):  
W. Lü ◽  
C. R. Li ◽  
Z. Zhang
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Band Structure ◽  
Quantum Wells ◽  
High Resolution Electron Microscopy ◽  
Multiple Quantum Wells ◽  
Electron Holography ◽  
Multiple Quantum ◽  
Resolution Electron

High Resolution Electron Microscopy of InGaAs/InAIAs Interfaces

1996 ◽  
Vol 54 ◽  
pp. 120-121
Author(s):  
G. Mountjoy ◽  
P.A. Crozier ◽  
P.L. Fejes ◽  
R.K. Tsui ◽  
G.D. Kramer
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Quantum Wells ◽  
High Resolution Electron Microscopy ◽  
Frequency Component ◽  
Chemical Imaging ◽  
Inp Substrate ◽  
Resolution Electron ◽  
Compositional Changes ◽  
Lattice Matched

Recently, quantum wells (QW) have been constructed using the (In0.532Ga0.468)As/ (In0.522Al0.478)As system (hereafter InGaAs/In Al As), which is lattice matched to InP (lattice constant of 5.869Å). In order to understand the properties of such QWs, it is important to have knowledge of the structure and composition of interfaces. For III-V materials, compositional changes affect the <200> frequency component of the high resolution electron microscopy (HREM) image intensity (I200). This underlies the “chemical imaging” approach. Simulations for InGaAs/InAlAs interfaces suggest optimum conditions of microscope defocus df=-50nm and sample thickness t=14nm in the <100> orientation. A double-QW structure, consisting of InGaAs/ InAlAs/ InGaAs layers with nominal thicknesses of 4nm/ 2nm/ 4nm (respectively), and embedded in InAlAs layers, has been studied. All the layers were grown by molecular beam epitaxy at 500°C on a <100> InP substrate, with 60s growth interrupts between layers in the QW region.

Strain mapping in MOSFETS by high-resolution electron microscopy and electron holography

2008 ◽  
Vol 154-155 ◽  
pp. 221-224 ◽  
Author(s):  
Florian Hüe ◽  
Martin Hytch ◽  
Florent Houdellier ◽  
Etienne Snoeck ◽  
Alain Claverie
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Electron Holography ◽  
Strain Mapping ◽  
Resolution Electron

Quantum Wells in Zn1-xCdxSe by High Resolution Electron Microscopy

2010 ◽  
Vol 16 (S2) ◽  
pp. 1734-1735
Author(s):  
HA Calderon ◽  
I Hernandez Calderon
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Quantum Wells ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

Electron microscopy of rabbit FC crystals

1983 ◽  
Vol 41 ◽  
pp. 730-731
Author(s):  
Robert A. Grant ◽  
Laura L. Degn ◽  
Wah Chiu ◽  
John Robinson
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Molecular Replacement ◽  
X Ray ◽  
X Ray Crystallography ◽  
Resolution Electron ◽  
Replacement Technique ◽  
Hydrated Crystal ◽  
Molecular Structure Analysis

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.

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