Hybrid Plasmonic Structures: Design and Fabrication by Laser Means

Design and fabrication of hybrid plasmonic structures by laser means are investigated to extend flexible tuning of optical properties of metallic micro/nano-structures for high-sensitivity detection and enhancement of solar cell antireflection performance for high energy-conversion efficiency. It is shown that the identical micro/nano-structures in well-defined arrays fabricated by laser interference lithography can be used as a versatile platform to enhance fluorescence intensity of the molecules. Meanwhile, postprocessing of such structures via thermal annealing can result in ordered clusters of nanodots 50 nm in average size, which enhances Raman scattering intensity. A dramatic reduction in silicon surface reflectance is achieved via pulsed fiber laser texturing. The suppression of reflectance can be further improved by decorating the laser-textured Si surface with metallic nanoparticles by thermal annealing of metallic thin films deposited on the Si surfaces. This hybrid plasmonic structure scheme can achieve broadband (300-1000 nm) antireflection with a surface reflection as low as 5.5%. The improved broadband antireflection of the surfaces could have applications in solar energy, renewable energy, and electrooptical devices.