Fabrication, characterization and simulation of non-lithographic nanostructures and their potential applications

The dissertation describes the formation of porous silicon through the pores of porous alumina on a silicon substrate. Porous silicon, by itself, is inherently a non-uniform material that has non-uniform optical and electronic properties. In addition, it is also mechanically fragile material requiring careful material handling. The porous silicon fabricated through the nanosized pores of porous alumina are expected to mitigate these problems, thereby enhancing commercial viability of the device. The porous silicon as well the porous alumina have been synthesized through anodisation for various parameters and also various types of anodizing electrolytes. The porous silicon, so obtained have been characterized through photoluminescence and Scanning Electron Microscopy. Further, applications of electropolished porous silicon, synthesized through the pores of porous alumina, as an anti-reflecting coating has been studied. The dissertation also studies the pulsed anodisation to synthesize thin film porous alumina with modulated diameters and their applications. Finally the dissertation also studies the simulations for the Surface enhanced Raman scattering in metal nanoparticles.