A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resona...

With HfO2 filled into the microcavities of the porous single-crystal silicon, the blue photoluminescence was greatly enhanced at room temperature. On one hand, HfO2 contributes to the light emission with the transitions of the defect levels for oxygen vacancy. On the other hand, the special filling-into-microcavities structure of HfO2 leads to the presence of ferroelectricity, which greatly enh...

We use single nanoparticle luminescence microscopy to determine a distribution of individual chromophores present in porous Si nanoparticles. From these distributions, we determine the average number of emitting chromophores in each nanoparticle and the fluorescence emission count rate of a single chromophore within the porous silicon nanoparticle. We also show that the same size nanoparticles ...

We have studied the influence of the end of range defects in silicon created by high energy protons and helium ions on subsequent porous silicon formation. The defect generation rate at the end of range is typically ten times higher than that close to the silicon surface. For low fluence irradiation, only the end-of-range region contains enough defects to prevent anodization whereas the low-def...

We present a fast, novel method for building porous silicon-based silicon-on-insulator photonic crystals in which a periodic modulation of the refractive index is built by alternating different electrochemical etching currents. The morphology and reflectance spectra of the photonic crystals, prepared by the proposed method, are investigated. The scanning electron micrograph and atomic force mic...

The purpose of this work is a detailed comparison of the fundamental magnetic properties of nanocomposite systems consisting of Fe3O4 nanoparticle-loaded porous silicon as well as silicon nanotubes. Such composite structures are of potential merit in the area of magnetically guided drug delivery. For magnetic systems to be utilized in biomedical applications, there are certain magnetic properti...

Porous Silicon Sensors have been fabricated and tested successfully over the last few years as humidity sensors, vapour sensors, gas sensors, piezoresistive pressure sensors and biosensors. In each case it has displayed remarkably sensitivity, relatively low temperature operation and ease of fabrication. Brief description of fabrication and properties of all these types of different sensors is ...

Structural order parameters of a smectic liquid crystal confined into the columnar form of porous silicon are studied using neutron scattering and optical spectroscopic techniques. It is shown that both the translational and orientational anisotropic properties of the confined phase strongly couple to the one-dimensional character of the porous silicon matrix. The influence of this confinement ...

Electrical and thermal modulation of porous silicon microcavities is demonstrated based on a change in the refractive index of liquid crystals infiltrated in the porous silicon matrix. Positive and negative anisotropy liquid crystals are investigated, leading to controllable tuning to both longer and shorter wavelengths. Extinction ratios greater than 10 dB have been demonstrated. Larger attenu...

Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. These porous nanowires also retain the crystallographic orientation of the wafer from which they are etched. Electron microscopy and diffraction confirm their s...