Directed Matrix Seeding of Semiconductor Nanostructures

Rachel S. Goldman

Professor

rsgold@umich.edu

2094 H.H. Dow Building

T: (734) 647-6821

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Matrix-seeded growth is a promising approach for synthesis of luminescent semiconductor nanocomposites, consisting of nanocrystals in an amorphous matrix. In this approach, a supersaturated-layer is produced by high-energy ion-implantation, and annealing leads to nanocrystallization in the matrix. We recently synthesized GaN-rich nanocrystals within an amorphous matrix using N-ion implantation into epitaxial GaAs, followed by rapid-thermal annealing. Remarkably, these nanostructures exhibit significant near-infrared photoluminescence and cathodoluminescence, indicating sufficient crystallinity for electronic and optoelectronic devices, such as high-sensitivity photodetectors and high-power field-effect transistors. At the core of this program is a novel approach to semiconductor nanopatterning, based upon our recent observation of preferential nanocrystallization at regions of highest ion damage. In the directed matrix seeding process, we will use Ga+ or In+ FIB implantation into Ga(In)As films, in order to produce nanoscale regions of preferential damage, which will act as crystallization "seeds". We will then use a combination of blanket and FIB implantation of N and Mn to facilitate the nucleation of N- and Mn-rich nanostructures upon annealing.