CPM Seminar

Nanowire Growth and Applications

Ray LaPierre

Department of Engineering Physics
McMaster University

Semiconductor nanowires are currently one of the “hottest” topics in physics, ranked number two by Nature in 2006. Semiconductor nanowires are essentially one-dimensional rods with length of several microns and diameter below 100 nm. Hence, nanowires exhibit interesting quantum confinement and carrier transport properties. In this seminar, I will present the growth and material related aspects of nanowires, along with the most recent applications. Nanowires are grown using metal seed particles by the vapor-liquid-solid (VLS) process in a molecular beam epitaxy or metal organic chemical vapor deposition system. By varying the material deposition during growth, axial or radial nanowire heterostructures and p-n junctions may be formed for various device applications. Due to the small contact area between a nanowire and its substrate, lattice mismatch strain may be accommodated by elastic distortion of the nanowire without detrimental misfit dislocations, which gives a greater degree of bandgap engineering in nanowires as compared to thin films. Hence, unique heterostructures are possible in nanowires that would be impossible in thin films such as GaAs/GaP and InAs/InP. This has opened up new device applications and possibilities in condensed matter physics. Our work in III-V nanowire heterostructures and applications in solar cells, photodetectors, quantum information processing, and sensors will be presented.