Strained Solid Films and Self Assembly of Quantum Dots

Faculty: Wondimu Tekalign

Summary:

Recent progress in lithography, colloidal chemistry and epitaxial growth has made it possible to fabricate structures in which carriers or excitons are confined in all three dimensions to a nanometer-sized region of a semiconductor.  Structures like these are commonly called quantum dots.  Fabrication of self assembled quantum dots begins with some form of atomic deposition onto the surface of a semiconductor substrate.  During the deposition process, epitaxial islands spontaneously form on the crystal surface (film surface). These islands have atom-like properties and therefore have potential applications in optical and optoelectronic devices, quantum computing, and information storage.  Electronic properties depend on regularity of dots, size and spacing. It is an open question as to whether natural self assembly can generate regular arrays of such dots.

Publications:

1. Evolution equation for a thin epitaxial film on a deformable substrate W.T. Tekalign and B.J. Spencer, J. Appl. Phys. 96, 5505 (2004).
   
   
2. Thin film evolution equation for a strained solid film on a deformable substrate: Numerical steady states, W.T. Tekalign and B.J. Spencer, J. Appl. Phys. 102, 073503 (2007). (Also selected for the Virtual Journal of Nanoscale Science and Technology, 10/15/07 issue)

Collaborators: Brian Spencer (SUNY Buffalo)