Séminaire du Groupe Physique

Characterization of Phosphorus Doped Silicon Nanocrystals Embedded in SiO2

October 17, 2013 – at 2pm – IEMN, LCI – Salle du Conseil

Sebastian Gutsch – University of Freiburg

Phosphorus (P) doped silicon nanocrystals (Si NCs)   are prepared by deposition and annealing of P doped silicon-rich oxide /   silicon oxide (SiO2) multilayers. The chemical environment of P is   determined from X-ray photoelectron and X-ray absorption near edge   spectroscopy. It is found that P is incorporated into the Si NCs down to   diameters of about 2.5 nm. However, the results suggest that essentially no   free electrons are generated in this doping process. Using atom probe   tomography, it is further found that large amounts of the dopants segregate   at the Si NC / SiO2 interface. In addition, photoluminescence   spectroscopy and electrical characterization of the multilayers indicate that   the majority of incorporated P atoms have only a small impact on the optical   and electronic properties. It is shown that less than 1% of the doped P atoms   occupy a substituitional site and that the donor ionization energy   significantly exceeds kT at room temperature.