A systematic analysis of HREM imaging of sphalerite semiconductors

Glaisher, R.W.; Spargo, A.E.C.; Smith, David J.

doi:10.1016/0304-3991(89)90082-x

Cited by 37 publications

(11 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The stacking of {111} planes across coherent twin boundaries can be viewed edge on along the 〈110〉 zone in HRTEM images. Glaisher et al (1989) proposed a method for determining the polarity from HRTEM images from an examination of contrast asymmetries in the lattice fringes as a function the thickness and defocus thickness. The projected distance between sublattices in beyond the resolving power of most medium-voltage HRTEMs (Phillipp et al, 1994a).…”

Section: Crystal Polarity Dislocations and Grain Boundariesmentioning

confidence: 99%

“…In the 〈110〉 projection, the shortest distance between the two sublattices is approximately 0.14 nm for most cubic III-V semiconductors. Imaging along the 〈110〉 zone, the intensity and phase of {111}, and {002} polar reflections acquire appreciable differences that vary with sample thickness (Glaisher et al, 1989). The inability to resolve the different sublattices precludes a direct determination of the crystal polarity from lattice fringes in HRTEM images.…”

Section: Crystal Polarity Dislocations and Grain Boundariesmentioning

confidence: 99%

“…The projected distance between sublattices in beyond the resolving power of most medium-voltage HRTEMs (Phillipp et al, 1994a). In principle, at specific values of defocus, HRTEM lattice-fringe contrast will shift toward one of the sublattices as the amount of dynamical scattering increases (Glaisher et al, 1989). Glaisher et al (1989) proposed a method for determining the polarity from HRTEM images from an examination of contrast asymmetries in the lattice fringes as a function the thickness and defocus thickness.…”

Section: Crystal Polarity Dislocations and Grain Boundariesmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

1999

View full text Add to dashboard Cite

: The measurement of absolute crystal polarity is crucial to understanding the structural properties of many planar defects in compound semiconductors. Grain boundaries, including twin boundaries, in the sphalerite lattice are uniquely characterized by the crystallographic misorientation of individual grains and the direction of the crystal polarity in domains adjoining the grain boundary. To evaluate crystal polarity in gallium phosphide (GaP), asymmetrical interference contrast in convergent-beam electron-diffraction (CBED) patterns was used to ascertain the nature and direction of polar bonds. The direction of the asymmetry in the electron diffraction reflections was correlated with the crystal polarity of a sample with known polarity. The CBED technique was applied to determine the polar orientation of grains adjoining Sigma = 3 coherent and lateral twin boundaries in polycrystalline GaP.

show abstract

Section: Crystal Polarity Dislocations and Grain Boundariesmentioning

confidence: 99%

Section: Crystal Polarity Dislocations and Grain Boundariesmentioning

confidence: 99%

Section: Crystal Polarity Dislocations and Grain Boundariesmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

1999

View full text Add to dashboard Cite

show abstract

“…Focal series reconstruction or iterative reconstruction of exit-plane wave is more suitable for structures and defects where atom positions are not clearly known. A combination of such techniques has been used successfully for imaging interfaces, partially tetrahedrally void filled semiconductors, oxides, solid-liquid interfaces [24,36,[39][40][41] etc. In the present case, as the atomic positions in cubic TiCr 2 Laves phase is known, simulated images could directly be matched with the experimental ones.…”

mentioning

confidence: 99%

Structure imaging and vanadium substitution in cubic TiCr₂Laves phase

Ghosh

Sharma

Basu

et al. 2015

Philosophical Magazine

View full text Add to dashboard Cite

Properties of Laves phase compounds can be tailored by alloying and microstructural engineering. V-substituted cubic TiCr 2 Laves phase has been studied to understand the location of V atoms in the lattice, by structural imaging and first-principle computations. Even though Ti, V and Cr appear next to each other in the periodic table, V preferentially replaces the Ti lattice producing anti-site defects. The defect formation energy for V substitution in Ti and in Cr lattice is 0.29 and 0.40 eV, respectively. V replacement in the Ti lattice generates atomic scale strain. Atomic numbers of V, Ti and Cr being very close, this phase is not quite suitable for incoherent imaging for understanding the structure and the chemistry. Instead, difference in channelling behaviour of electron waves along the Ti columns and along the Cr columns could be exploited to preferentially image the individual atom columns. Nature of the exit phase wave, phase and amplitude has been used to understand the contrast qualitatively. The intensity distribution of any particular atom column that is disturbed by the presence of foreign atom has been used to detect the position of V atoms. This method could be extended to study other Laves phases and complex intermetallic structures to understand their structure, defects and interfaces. IntroductionLaves phases, a group of topologically close-pack hard intermetallic compounds with AB 2 stoichiometry, are known to form at a particular radius ratio of A and B (r A /r B = 1.22) atoms [1]. However, a considerable deviation from ideal radius ratio (r A /r B = 1.05-1.67) [2] is observed in practice and the phase can often accommodate non-stoichiometry [3]. There are three allotropic polymorphs of Laves phase i.e. cubic (cF24), hexagonal (hP12) and double-hexagonal (hP24) [2]. Since the discovery of this phase, more than a thousand binary and ternary Laves phase forming compounds with a range of interesting properties and varying crystal chemistry have been reported in the literature [4]. These attributes could be exploited to design single-phase or multiphase

show abstract

“…The <110> projection is most often used for examination of semiconductor interfaces and growth defects, and crystal polarity can usually be determined by studying the characteristic image appearance at certain thicknesses and objective-lens defocus settings. 5 However, individual atomic columns, often referred to as ''dumbbells,'' 6 cannot be separately resolved when imaging in this projection unless {004}-type reflections contribute to the image formation process. This performance requirement is quite demanding and could initially only be achieved by dedicated high-voltage, high-resolution electron microscopes.…”

Section: Introductionmentioning

confidence: 99%

Atomic-Scale Characterization of II–VI Compound Semiconductors

Smith

2013

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

Alloys of II-VI compound semiconductors with suitable band gap selection potentially provide broad coverage of wavelengths for photodetector applications. Achievement of high-quality epitaxial growth is, however, essential for successful development of integrated photonic and optoelectronic devices. Atomic-scale characterization of structural defects in II-VI heterostructures using electron microscopy plays an invaluable role in accomplishing this goal. This paper reviews some recent high-resolution studies of II-VI compound semiconductors with zincblende crystal structure, as grown epitaxially on commonly used substrates. Exploratory studies using aberration-corrected electron microscopes are also briefly considered.

show abstract

A systematic analysis of HREM imaging of sphalerite semiconductors

Cited by 37 publications

References 11 publications

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

Structure imaging and vanadium substitution in cubic TiCr₂Laves phase

Atomic-Scale Characterization of II–VI Compound Semiconductors

Contact Info

Product

Resources

About

A systematic analysis of HREM imaging of sphalerite semiconductors

Cited by 37 publications

References 11 publications

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

Structure imaging and vanadium substitution in cubic TiCr2Laves phase

Atomic-Scale Characterization of II–VI Compound Semiconductors

Contact Info

Product

Resources

About

Structure imaging and vanadium substitution in cubic TiCr₂Laves phase