Professor Zbig Wasilewski and Trevor Blaikie, a graduate student in the QNC-MBE Group, visited the Canadian Light Source (CLS) synchrotron facility of the University of Saskatchewan in Saskatoon to perform resonant X-ray diffraction (XRD) scans using the synchrotron radiation. Such XRD scans provide further information than the XRD machine in the QNC-MBE Lab.
Experiments were performed on two molecular beam epitaxial growth structures during this trip. The first structure is InSb films on GaAs substrates. The anisotropy of the InSb Bragg peak broadening was studied using the array detector of the CLS diffractometer for 3D reciprocal space maps. The anisotropy of the Bragg peak broadening provides us with rich information on the distribution of the strain field and defects in the films. The second kind of structure is a number of different superlattice structures, including some quantum cascade lasers (QCL). The quality of the interfaces of these superlattices was investigated. Since each superlattice structure was grown with different growth conditions, this study points us in directions to improve the operation of the QCLs.
This is an excellent opportunity for graduate students to learn at one of the greatest science facilities in Canada. Many more trips to CLS for the characterization of many other material systems are to be scheduled.