Regensburg 1998 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 43: Quantenpunkte III
HL 43.8: Vortrag
Freitag, 27. März 1998, 13:15–13:30, H1
Quantitative analysis of lattice distortion in quantum structures from high resolution electron microscope (HRTEM) images — •Y. Hao1, N. Y. Jin-Phillipp1, F. Phillipp1, M. Zundel2, and K. Eberl2 — 1Max-Planck-Institut für Metallforschung — 2Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart
The knowledge of the local chemical composition and the lattice distortions in semiconductor quantum systems is essential for the understanding of the growth mechanisms as well as the electronical and optical properties. In order to get such information, a PV-WAVE supported program package has been developed which allows to analyse the local lattice distortions of coherent structures directly from HRTEM micrographs, i.e., without the need of image simulations, and has been applied to the analysis of quantum-dot structures in the GaInAs/GaAs and InP/GaInP systems. The program is based on the comparison of HRTEM lattice images in the area of the quantum dots with a reference lattice, which is generated from an undistorted region. Various program modules provide the possibility to analyse locally the tetragonal- and shear components of the distortions and the variation of the local lattice parameters within the quantum dots and in surrounding matrix areas. Thus, a comprehensive understanding of the lattice deformation is achieved which serves as a base for the modeling of growth and alignment of self-assembling quantum dots and the determination of the local chemical composition.