In this talk, we will present metamaterial based nanobiosensors, nanophotodetectors and perfect absorbers. Our results show that a plasmonic structure can be successfully applied to bio-sensing applications and extended to the detection of specific bacteria species. A highly tunable design for obtaining double resonance substrates to be used in Surface Enhanced Raman Spectroscopy will also be presented. Surface Enhanced Raman Scattering experiments are conducted to compare the enhancements obtained from double resonance substrates to those obtained from single resonance gold truncated nano-cones. We will present a UV plasmonic antenna integrated metal semiconductor metal (MSM) photodetector based on GaN. We designed and fabricated Al grating structures. Well defined plasmonic resonances are measured in the reflectance spectra. Optimized grating structure integrated photodetectors exhibit more than eight-fold photocurrent enhancement. We also demonstrate a facile, lithography free, and large scale compatible fabrication route to fabricate ultra-broadband wide angle perfect absorber based on metal-insulator-metal-insulator (MIMI) stack design. 600 nm band-width (400 nm – 1000 nm) is attained utilizing this planar design. This design is later improved by introduction of non-uniform texturing and employing disordered nano hole plasmonic patterns where the overall process is large scale compatible and lithography free. Our findings show that the optimized design can retain light absorption above 90% over a wide range wavelength of 400 nm – 1490 nm. To the best of our knowledge, this bandwidth is the highest among other reported studies that employ such multilayer architectures.
|