Research Interests

Si and Ge quantum dots

Electronic and optical properties of Si and Ge quantum dots

Among quantum emitters semiconductor quantum dots (QD) have the highest emission rates and can be most easily integrated with semiconductor technology. QD emission properties often degrade because of various imperfections at the QD-dielectric interface. We investigate the electronic states and optical properties of Si and Ge quantum dots with variable size prepared by ion implantation in dielectic matrix by ion beam analysis, x-ray photoemission spectroscopy (XPS), photoluminescence (PL), and Raman spectroscopy. Learn more here...

...in collaboration with Peter Simpson

Quantum Confinement Models in Si and Ge Nanostructures

We use perturbative effective mass theory as a toy theoretical model for quantum confinement(QC) in Si and Ge quantum wells (QWs), wires (Q-wires) and dots (QDs). Learn more here...

...in collaboration with David J. Lockwood, NRC

Nanoporous anodic Al₂O₃ films as ion implantation masks

As a part of a larger project nanoporous Al₂O₃ films are developed as ion implantation masks to control lateral distribution and size of Si quantum dots. The ultrathin PAA films will be used in further experiments to explore its application to form silicon nanocrystal arrays as well as to characterize its damage profile upon bombardment with silicon and gold ions.

High-resolution ion beam analysis: transport and reactivity

Exchange and interface growth in high-k dielectric stacks by medium energy ion scattering

Medium energy ion scattering has been used in combination with ¹⁶O and ¹⁸O isotope tracing to determine elemental depth distributions and elucidate oxygen transport in 2–5 nm thick HfO₂ and HfSiO_x films grown by atomic layer deposition on Si(001). Both the oxygen isotope exchange rate in the dielectric as well as the interfacial silicon oxide growth rates were examined as a function of time, temperature, film stoichiometry , and crystallinity.
Learn more here...

Diffusion of H/D in thin film materials using ERDA

Under construction...

Medium energy ion scattering (MEIS) and cold-neutron depth profiling (NDP) as a research tool for the study of surface oxides on metals

A recent experiment at NIST has demonstrated that NDP based on the (n, a) reaction could be developed into a tool that could be routinely used for the study of passive oxides on metals. Whereas most metals are not (n, a) active, oxides grown with 17O, the only (n, a) active oxygen isotope, can be observed and tracked by this technique. Parallel (MEIS vs NDP) studies will be conducted to look at the oxidation rate in titanium. Learn more here...

...in collaboration with Z. Tun (NRC, Chalk River), J.J. Noel (Chemistry, UWO)

Modification of low-dimensional materials properties using ion beams

Modification of electrical and magnetic properteis of carbon-based materials

Under construction...