Instytut Podstawowych Problemów Techniki
Polskiej Akademii Nauk


J. Kioseoglou

Aristotle University of Thessaloniki (GR)

Ostatnie publikacje
1.  Dimitrakopulos G.P., Kalesaki E., Kioseoglou J., Kehagias T., Lotsari A., Lahourcade L., Monroy E., Häusler I., Kirmse H., Neumann W., Jurczak G., Young T.D., Dłużewski P., Komninou Ph., Karakostas T., Morphology and strain of self-assembled semi-polar GaN quantum dots in (1112) AlN, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/1.3506686, Vol.108, pp.104304-1-9, 2010

GaN quantum dots (QDs) grown in semipolar (11-22) AlN by plasma-assisted molecular-beam epitaxy were studied by transmission electron microscopy (TEM) and scanning transmission electron microscopy techniques. The embedded (11-2)-grown QDs exhibited pyramidal or truncated-pyramidal morphology consistent with the symmetry of the nucleating plane, and were delimited by nonpolar and semipolar nanofacets. It was also found that, in addition to the (11-22) surface, QDs nucleated at depressions comprising {10-11} facets. This was justified by ab initio density functional theory calculations showing that such GaN/AlN facets are of lower energy compared to (11-22). Based on quantitative high-resolution TEM strain measurements, the three-dimensional QD strain state was analyzed using finite-element simulations. The internal electrostatic field was then estimated, showing small potential drop along the growth direction, and limited localization at most QD interfaces.

Słowa kluczowe:
Quantum dots, Transmission electron microscopy, III-V semiconductors, High resolution transmission electron microscopy, Epitaxy

Afiliacje autorów:
Dimitrakopulos G.P. - Aristotle University of Thessaloniki (GR)
Kalesaki E. - Aristotle University of Thessaloniki (GR)
Kioseoglou J. - Aristotle University of Thessaloniki (GR)
Kehagias T. - Aristotle University of Thessaloniki (GR)
Lotsari A. - Aristotle University of Thessaloniki (GR)
Lahourcade L. - CNRS (FR)
Monroy E. - CNRS (FR)
Häusler I. - Humboldt-Universität zu Berlin (DE)
Kirmse H. - Humboldt-Universität zu Berlin (DE)
Neumann W. - Humboldt-Universität zu Berlin (DE)
Jurczak G. - IPPT PAN
Young T.D. - IPPT PAN
Dłużewski P. - IPPT PAN
Komninou Ph. - Aristotle University of Thessaloniki (GR)
Karakostas T. - Aristotle University of Thessaloniki (GR)
2.  Young T.D., Kioseoglou J., Dimitrakopulos G.P., Dłużewski P., Komninou Ph., 3D modelling of misfit networks in the interface region of heterostructures, JOURNAL OF PHYSICS D-APPLIED PHYSICS, ISSN: 0022-3727, DOI: 10.1088/0022-3727/40/13/027, Vol.40, pp.4084-4091, 2007

We present a methodology for the stress–strain analysis of a film/substrate interface by combining crystallographic and continuum modelling. Starting from measurements of lattice parameters available from experimental observations, the heterostructure is recast initially in the form of a crystallographic model and finally as a continuum elastic model. The derived method is capable of handling dense arrays of misfit dislocations as well as large areas of the interface between two crystal structures. As an application we consider the misfit dislocation network in the GaN/Al2O3 interface region through determination of strain relaxation and associated residual stresses. Our calculated results are referred back to and found to be in good agreement with the experimental observations of misfit dislocation arrays obtained from high resolution transmission electron microscopy.

Afiliacje autorów:
Young T.D. - IPPT PAN
Kioseoglou J. - Aristotle University of Thessaloniki (GR)
Dimitrakopulos G.P. - Aristotle University of Thessaloniki (GR)
Dłużewski P. - IPPT PAN
Komninou Ph. - Aristotle University of Thessaloniki (GR)

Lista rozdziałów w ostatnich monografiach
Dłużewski P., Young T.D., Dimitakopulos G., Kioseoglou J., Komninou Ph., Computer Methods in Mechanics, Advanced Structured Materials, rozdział: Nonlinear finite element and atomistic modelling of dislocations in heterostructures, Springer Verlag, Kuczma M., Wilmański K. (Eds.), 1/III, pp.239-253, 2010

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