Electrical and Computer Engineering
Dean of Engineering
FOM Institute AMLOF, Amsterdam
IEEE Photonics Seminar - “Solar highways: core-shell nanowires for high-efficiency solar conversion"
Tuesday, May 6, 2014
to 5:00 PM
1070 Duncan Hall
6100 Main St
Houston, Texas, USA
The ideal solar cell fuel device would convert light into photogenerated carriers in an infinitely small volume. Such a structure not only limits material usage but also relaxes carrier diffusion length requirements and maximizes the output voltage. Here we describe a novel geometry consisting of a metal nanowire covered by an ultrathin semiconductor layer, which shows extreme light absorption enhancement. We present a theoretical model to explain why this structure works so well in both polarizations of light and use full-field simulations to demonstrate robust performance even with geometrical perturbations. We begin experimental work with a model system consisting of a silver nanowire core and cuprous oxide shell. These core-shell nanowires are synthesized at low temperature in solution and here we will present electron microscopy showing that they are single-crystalline with atomically sharp and coherent interfaces. Finally, we will present spatially-resolved, single nanowire optical measurements (reflection, scattering, absorption) taken using an integrating sphere and compare the results quantitatively to simulations. Our experiments suggest that this solar highways geometry should be explored further for photovoltaics and solar fuels applications.
Biography of Erik Garnett:
Erik Garnett received his BS in chemistry from the University of Illinois, Urbana-Champaign (2004) and his PhD from the University of California, Berkeley in Chemistry (2009) under the direction of Professor Peidong Yang. He then moved to Stanford University for postdoctoral research in the Materials Science and Engineering department with Professors Mark Brongersma, Yi Cui and Mike McGehee. In 2012, Erik joined the faculty of FOM-AMOLF in Amsterdam to start a new research direction for the institute related to nanomaterials and light trapping for solar energy conversion. His “Nanoscale Solar Cells” group studies fundamental aspects of synthesis, materials characterization and device integration of nanomaterials with the aim of increasing the efficiency and reducing the cost of solar energy. Erik was recently awarded an ERC starting grant from the European Union for this work.