Séminaire "Hyper-dimensional nanowire metamaterials for energy, photonic, and defense applications" par le Professeur Ray R. LaPierre de McMaster University

Hyper-dimensional nanowire metamaterials for energy, photonic, and defense applications

Ray R. LaPierre (E-mail: lapierr@mcmaster.ca)

Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada, L8S 4L7

Semiconductor nanowires (NWs) are being developed for the next generation of optoelectronic devices such as photodetectors, photovoltaics, betavoltaics and thermoelectrics. The self-assisted vapor-liquid-solid method is now a well-established technique for the growth of group III-V compound semiconductor NWs. In this method, an array of holes in a SiO₂ film is used for metal droplet formation, which seeds the growth of vertically oriented NWs within a periodic array. The free lateral surfaces of NWs allow elastic relaxation of lattice misfit strain without the generation of dislocations, permitting unique heterostructures and the direct integration of III-V materials with silicon substrates. Furthermore, NWs permit high optical absorption due to an optical antenna effect. The optical absorption in NW arrays can exceed that due to a thin film of equivalent thickness, enabling high efficiency NW-based photonic devices. The next evolution in NW growth and applications will be presented – namely, hyper-dimensional nanowires, where the diameter of NWs can be controlled at will, creating oscillatory NWs for photonic, energy and defense applications.