1차원 광학 Multilayer 다공성 실리콘 / 광학 고분자 Replicas

Abstract

Chapter 1. Hydrosilylation for both n-type and p-type porous silicon has been investigated with alkene such as 1-octene, 1-decene, and 1-dodecene, under three different conditions. Etching was carried out as a two-electrode galvanostatic procedure at an anodic current density. The photolytic hydrosilylation of porous silicon using two different types of light sources, 300W tungsten halogen lamp (white light) and UV lamp (350nm), and thermal hydrosilylation (110 oC in toluene) were used to determine the efficiency of the surface coverage of porous silicon. Surface characterization of silylated porous silicon was achieved using FT-IR instrument by measuring the areas for the alkyl regions. The effect of photoluminescence and reflectivity upon hydrosilylation was also investigated. Hydrosilylation of p-type porous silicon exhibited red shift of Fabry-Perot fringe and indicated that the pore structure of porous silicon remained robust. While hydrosilylation of n-type porous silicon exhibited the decrease of photoluminescence, hydrosilylation using 300W white light showed the least decrease of photoluminescence. The efficiency of hydrosilylation in UV irradiation exhibited much better than that in 300W tungsten halogen lamp. 20-60% efficiency of hydrosilylation has been obtained from FTIR. Chapter 2. The development of new technology, which can achieve at nanometer scale, to build a device is of great interest, because it is too complex to fabricate by using conventional lithographic method. Multi-structured porous silicon (PSi) is very attractive material because of its optical signal transduction capability. The unique optical properties of PSi have been investigated for a variety of chemical and biological sensing applications. The chemical modification of PSi exhibits the modification of its physical, chemical, and electronic properties. Here we have prepared multilayer(Bragg, Rugate) photonic structure by a galvanostatic anodic etch of crystalline silicon wafer. DBR PSi having the photonic structure of a Bragg filter can be generated by applying a computer generated square current density waveform. Also, rugate PSi can be generated by applying a computer generated pseudo-sinusoidal current density waveform. Multilayer PSi exhibits unique optical properties and exhibits photonic structure of Bragg filters which result in a mirror with high reflectivity in a narrow spectral region. This reflective wavelength can be controlled by tuning of etching time and can appear anywhere in the visible range depending on the square and sine waveform. This might be a demonstration for the fabrication of specific reflectors or filters in full color. Chapter 3. Synthesis of nanostructured materials has emerged as a useful and versatile technique to provide the use of encoded materials for chemical and biological sensors, high throughput screening, and controlled release drug delivery. Since the discovery of porous silicon(PSi) from silicon wafer, research has been associated with emerging technologies, such as photonic crystals for opticals for band pass filters and micro chemical reaction applications in micro chemical and micro fuel cells. Rugate PSi is an attractive candidate for building nanostructured composite materials because the porosity and average pore size can be tuned by adjusting the electrochemical preparation conditions that allow the construction of photonic crystals. Rugate PSi can be generated by applying a computer generated pseudo-sinusoidal current density waveform. Rugate PSi exhibits unique optical properties. The resulting rugate PSi films can be lifted off from the silicon substrate to obtain a free-standing rugate PSi films. For many applications, free-standing rugate PSi is limited by its chemical and mechanical stability. Because these free-standing films are very brittle. Here, we have prepared polymer replicas showing a desired reflectivity by the casting of polymer solution onto a porous silicon dioxide multilayer and provides the means for the construction of complex photonic structures with polymers. The photonic polymer replicas showing a desired reflectivity by casting of polymer solution onto a porous silicon dioxide multilayer have been prepared. The photonic polymer replicas are robust in ambient condition and exhibit an excellent reflectivity in their reflective spectra. The photonic band gaps of replicas are narrower than that of typical semiconductor quantum dots. The means for the construction of complex photonic structures with polymers have been provide. Chapter 4. Synthesis of nanostructured materials has emerged as a useful and versatile technique to provide the use of encoded materials for chemical and biological sensors, high throughput screening, and controlled release drug delivery. Since the discovery of porous silicon(PSi) from silicon wafer, research has been associated with emerging technologies, such as photonic crystals for opticals for band pass filters and micro chemical reaction applications in micro chemical and micro fuel cells. DBR(Distributed Bragg reflector) PSi is an attractive candidate for building nanostructured composite materials because the porosity and average pore size can be tuned by adjusting the electrochemical preparation conditions that allow the construction of photonic crystals. DBR PSi has been typically prepared by an applying a computer generated pseudo-square current waveform to the etch cell which results two distinct indices and exbibits photonic structure of Bragg filters. DBR PSi exhibits unique optical properties. For many applications, free-standing rugate PSi is limited by its chemical and mechanical stability. Because these free-standing films are very brittle. The use of flexible DBR PSi/polymer composite materials eliminates these issues and improves chemical and mechanical stability. However, these composite materials are not suitable for the application of biological sensors in vivo due to the presence of silicon metal from the PSi films. Therefore, biocompatible polymers having a specific optical characteristics would be ideal for these applications. Here, we have prepared polymer replicas showing a desired reflectivity by the casting of polymer solution onto a porous silicon dioxide multilayer and provides the means for the construction of complex photonic structures with polymers. The photonic polymer replicas showing a desired reflectivity by casting of polymer solution onto a porous silicon dioxide multilayer have been prepared. The photonic polymer replicas are robust in ambient condition and exhibit an excellent reflectivity in their reflective spectra. The photonic band gaps of replicas are narrower than that of typical semiconductor quantum dots. The means for the construction of complex photonic structures with polymers have been provide.