Nanophotonic Materials and Devices for Solar Energy and Bio-sensing Applications

K. Aydin
Northwestern University, US

Keywords: nanopotonic materials, solar, bio-sensing

Summary:

Nanophotonics, the emerging field of photon-material interactions at the nanoscale, poses many challenges and opportunities for researchers engineering devices with subwavelength features. Plasmonic nanostructures and metamaterials exhibit optical properties not seen in conventional photonic materials and enable focusing, guiding, bending, and absorbing photons at the nanoscale. They are poised to revolutionize a broad range of applications including energy and sensing. In this talk, I will describe the design, nanofabrication and optical characterization of engineered nanophotonic materials that enable controlled and enhanced photonic functionalities. First, I will discuss flexible, stretchable metamaterials in which the mechanical actuation of flexible polymers can be used to control the nanoscale distances between coupled metallic resonators. Such reconfigurable, smart nanophotonic materials significantly enhance the infrared reflection signal from a C-H vibrational mode, could find use in bio-chemical sensing and environmental screening applications. We observed 180-fold increase in the sensitivity of infrared absorption detection. As a second application of optical metamaterials, I will discuss broadband light-trapping approaches enabled by the unique metal nanostructure design and nanofabrication. Ultrathin, polarization-insensitive, broadband metamaterial super absorbers capable of absorbing light over the entire visible spectrum will be discussed in detail. Moreover, nanostructured semiconductors and transparent conductive oxides that enable drastic enhancements in solar light absorption will be described.