Nanoanalytics

Interfaces in low-dimensional heterostructures and nano-systems

A central goal of modern artificial heterostructures and nanomaterials is the control of interfaces due to their crucial effect on both physical properties and device performances. The detailed analysis of morphology and intermixing of hetero-interfaces allows a better control during growth and opens the possibility to tune the interface property with functionality in nano-structured materials.  High-resolution and analytical transmission electron microscopy techniques are used to determine quantitatively the interface structure and interfacial composition with highest spatial resolution. Hetero-interfaces are coherent or semi-coherent depending on the epitaxial strain. Atomic configurations along coherent interfaces were determined quantitatively in comparison with theoretical models and simulations (Abb.1). On the other hand, misfit dislocations along semi-coherent interfaces define the strain state as well as the associated detrimental threading defects in the films.

 

In addition, coherent interfaces in III-V semiconductor heterostructures are generally characterized by the structural roughness and the chemical intermixing, which can be quantified by composition profiles. We found that the experimentally determined concentration dependence for the transition region at interfaces follows a sigmoidal law (Abb. 2) and constitutes a universal behavior regardless of the semiconductor system.

Selected Publications

3 Author E. Luna , A. Guzman , A. Trampert , G. Alvarez
Title

Critical role of two-dimensional island-mediated growth on the formation of semiconductor heterointerfaces

Source Phys. Rev. Lett. , 109 , 126101 ( 2012 )
Download: PDF | 2325 Cite : Bibtex RIS
E. Luna, A. Guzman, A. Trampert, and G. Alvarez

2 Author M. Niehle , A. Trampert
Title

Atomic interface structure of bixbyite rare-earth sesquioxides grown epitaxially on Si(111)

Source J. Phys. D , 45 , 295302 ( 2012 )
2281 Cite : Bibtex RIS
M. Niehle, and A. Trampert

1 Author Q. Wan , A. Trampert
Title

Atomic configuration of the MnAs/GaAs(110) interface analyzed by high-resolution electron microscopy

Source J. Phys. Chem. C , 115 , 529 ( 2011 )
2178 Cite : Bibtex RIS
Q. Wan, and A. Trampert

Contact

Dr. Achim Trampert

Head of Department 

+49 30 20377-280

trampert@pdi-berlin.de