Grant: Research Tools and Instruments - Category 1 (<$150,000)

Crystalline semiconductors are the foundation of telecommunications, computing, and many other technologies employed in all aspects of contemporary life. Their physical characteristics are determined both by the properties of the host crystal and by the presence of impurities and crystalline defects. The identification and control of these defects determines the commercial viability of a given new material or structure. Combined with control of growth and processing factors, the influence of crystalline defects and impurities at surfaces, interfaces and in the bulk semiconductor can be distinguished and enhanced or eliminated. A new capability to make extremely sensitive electrical measurements at temperatures below 80K is needed to extend the energy range of carrier trapping experiments and also to investigate the effects of surfaces and interfaces on transport properties in novel nanostructures, including nanowires. We request funding to acquire a closed-cycle He cryostat for electrical measurements of a variety of semiconductors and nanostructures in the temperature range 4-300K. In addition, we propose to purchase an electrical measurement system capable of detecting electrical currents as low as 10 to the power -15 Amperes (1fA), required for studies of their electronic properties. The applicants, including two CRC Chairs, have established outstanding research programs based on existing facilities in their individual laboratories (e.g. Watkins' MOCVD laboratory and Mooney's Semiconductor Defect Spectroscopy Laboratory) and on shared SFU facilities such as 4DLABs Nanofabrication Facility (Gates is Director) and the Nanoimaging Facility (Kavanagh is Director). They have the expertise and facilities for semiconductor epitaxial growth, solution synthesis of nanowires, contact fabrication, and investigation of optical and structural properties, as well as facilities for investigating magneto-transport properties and carrier trapping at defects. However, at present carrier trapping measurements can be done only at temperatures above 80K, which limits the energy range that can be investigated. Graduate students and postdoctoral researchers will use this equipment in carrying out a variety of current projects.