Flexible thin-film black gold membranes with ultrabroadband plasmonic nanofocusing for efficient solar vapour generation

Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light absorption and high plasmon dissipation loss. Here we demonstrate large area, flexible thin-film black gold membranes, which have multiscale structures of varying metallic nanoscale gaps (0-200 nm) as well as microscale funnel structures. The adiabatic nanofocusing of self-aggregated metallic nanowire bundle arrays produces average absorption of 91% at 400-2,500 nm and the…

• NR
  National Research Foundation
• MO
  Ministry of Science, ICT and Future Planning
• NR
  National Research Foundation of Korea

  Awards: 2015R1A2A2A11001112, NRF-2015R1A2A2A11001112, 2013M3C1A3065045, NRF-2013M3C1A3065045
• AF
  Agency for Defense Development
• DA
  Defense Acquisition Program Administration