BOWLER1	Adsorption of ammonia on prepared silicon surfaces
Type	Theoretical
#students	1
Orientation	Why is the scientific problem of interest at all? It is now possible, using an STM tip, to define lithographically holes in a hydrogen layer on a silicon surface with atomic precision, and then to adsorb gases and more silicon. We are working with a company in the USA who are using this technique to grow nanostructures of silicon and other materials (e.g. boron and germanium) with atomic precision, by performing chemical vapout deposition (CVD) on these holes to grow the structures layer-by- layer.
How	How is the research going to shed light on the given problem?. However, we need to understand how the precursors will adsorb, decompose, react and move on the surface.  Once these quantities are known, the experiments will be better controlled, and the precision and placement of the atoms will be enhanced.
What	What is the specific thing that the student will do, and how does it fit inside the overall project? You will use state-of-the- art electronic structure techniques to calculate the process of adsorption of ammonia onto holes in the hydrogen layer, and to investigate the effects of dopants in the surface on this adsorption.  This research will help us understand how to control the deposition of N onto silicon, either for growth of nitride nanostructures, or as a contrast to more commonly used Group V dopants.
Special Knowledge	The project is based around computational simulations, and the student will be expected to learn how to use Unix-based operating systems as well as density functional theory codes.  An interest in computing and computational and/or theoretical physics would be an advantage.
Supervisor	Dr David Bowler david.bowler@ucl.ac.uk