Chemical Nano-Tomography of Self-Assembled Ge-Si:Si(001) Islands From Quantitative High Resolution Transmission Electron Microscopy

Author(s):Show less -

Montoro, Luciano A. ; Leite, Marina S. ; Biggemann, Daniel ; Peternella, Fellipe G. ; Batenburg, K. Joost ; Medeiros-Ribeiro, Gilberto ; Ramirez, Antonio J. ; Moeck, P ; Hovmoller, S ; Nicolopoulos, S ; Rouvimov, S ; Petkov, V ; Gateshki, M ; Fraundorf, P

• Document type: Journal article
• Source: HYDROGEN CYCLE-GENERATION, STORAGE AND FUEL CELLS; v. 1184, p. 3-pg., 2009-01-01.

Abstract

The knowledge of composition and strain with high spatial resolution is highly important for the understanding of the chemical and electronic properties of alloyed nanostructures. Several applications require a precise knowledge of both composition and strain, which can only be extracted by self-consistent methodologies. Here, we demonstrate the use of a quantitative high resolution transmission electron microscopy (QHRTEM) technique to obtain two-dimensional (2D) projected chemical maps of epitaxially grown Ge-Si:Si(001) islands, with high spatial resolution, at different crystallographic. orientations. By a combination of these data with an iterative simulation, it was possible infer the three-dimensional (3D) chemical arrangement oil the strained Ge-Si:Si(001) islands, showing a four-fold chemical distribution which follows the nanocrystal shape/symmetry. This methodology can be applied for a large variety of strained crystalline systems, such as nanowires, epitaxial islands, quantum dots and wells, and partially relaxed heterostructures. (AU)

• FAPESP's process: 07/05165-7 - Quantitative transmission electron microscopy (QHRTEM): developments and application to a study of a nanostructured semiconductor
• Grantee: Luciano Andrey Montoro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral