Professor Stephen Urquhart BSc, PhD, PChem

I am a Professor of Chemistry and an associate member of the Department of Physics. I supervise Chemistry and Physics undergraduate and graduate students and postdoctoral fellows and teach physical and introductory chemistry courses. 

My research is focused on applied and fundamental aspects of X-ray spectroscopy and microscopy, ranging from fundamental molecular spectroscopy to the structural properties of organic nanomaterials and semiconductor devices. My research group is involved in the development of the Spectromicroscopy beamline at the Canadian Light Source.

International students should provide evidence of English Language competency as part of their cover letter. Strong communication skills are essential to research success for all students.

I am active in the professional development and professional self-regulation, serving as secretary of the Association of Chemistry Profession of  the Saskatchewan (ACPS, www.saskpchem.ca).

My research uses the tools of x-ray absorption spectroscopy and x-ray microscopy to study the structure and properties of materials. Scanning Transmission X-ray Microscopy (STXM) and PhotoElectron Emission Microscopy (PEEM) are forms of chemical imaging that combine the chemical sensitivity of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy with high spatial resolution x-ray microscopy (35-50 nm spatial resolution for STXM). X-ray spectromicroscopy is developing as a valuable complement to traditional electron and scanned probe microscopy for materials research. My research is focused in two areas:

• Materials Chemistry
  We use X-ray microscopy to study the structure and composition of complex, nanostructured materials, with an eye to understanding the thermodynamics and kinetics of nanostructure formation. Organic nanostructures are of particular interest, where we use epitaxy to control and pattern molecular orientation at microscopic length scales. We also study how semiconductor strain effects the light emitting properties of nanocrystalline silicon (in collaboration with Group IV Semiconductor; NSERC SPG funding) and phase separated Langmuir Blodgett thin films (in collaboration with M. Paige, Chemistry) 
• Molecular Spectroscopy 
  The chemical sensitivity of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy provides the exquisite sensitivity of x-ray microscopy for basic and applied materials chemistry analysis, particularly as it can provide detailed and quantitative chemical information at high spatial resolution (e.g. below 50 nm). My research combines experimental and computational studies to understand the structure - spectral relationships for organic molecules. These questions range from the practical to the esoteric, such as the nature of "matrix effects" in condensed molecules, orientation dependence in complex organic molecules, and the natural circular dichroism of chiral organic molecules at x-ray wavelengths.

Third-generation synchrotron sources such as the Canadian Light Source offer new opportunities for materials analysis and for fundamental spectroscopy. I am closely involved in the development of new spectromicroscopy at the Canadian Light Source, consisting of an Elliptically Polarized Undulator (EPU) source, and two state-of-the-art x-ray microscopes, a Photoelectron emission microscope (PEEM) and a Scanning Transmission X-ray Microscope (STXM).

• Ph.D., McMaster University, July 1997
• B.Sc., McMaster University, April 1992