Surface plasmon enhanced broadband spectrophotometry on black silver substrates

We demonstrate surface plasmon-induced enhancements in optical imaging and spectroscopy on silver coated silicon nanocones which we call black silver. The black silver with dense and homogeneous nanocone forest structure is fabricated with a mass-producible nanomanufacturing method. It can efficiently trap and convert incident photons into localized plasmons in broad wavelength range, permitting the enhancement in optical absorption from ultraviolet to near infrared range by 12 times, the visible fluorescence enhancement of similar to 30 times and the Raman scattering enhancement factor up to similar to 10(8). We show the potential of the black silver in high sensitivity and broadband optical sensing of molecules. (C) 2011 American Institute of Physics. [doi:10.1063/1.3599551]