Microstructural evolution and biological performance of Cu-incorporated TiO2 coating fabricated through one-step micro-arc oxidation

Porous silicon (PS) layers are prepared by anodization for different current densities. The samples are then characterized the nanocrystalline porous silicon layer by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR), Reflectivity and Raman. PS layers were formed on a p-type Si wafer. anodized electrically with a 10 and 40 mA/cm 2 current density for fixed 20 min etching times. We have estimated crystallites size from X-Ray diffraction about nanoscale for porous silicon and AFM confirms the nanometric size and therefore optical properties about nanocrystalline silicon yields a Raman spectrum showing a broadened peak shifted below 520 cm -1 .

/pdf/characteristics-of-nanostructure-porous-silicon-prepared-by-3tz0nyb8ne.pdf

Characteristics of Nanostructure Porous Silicon Prepared by Anodization Technique

https://iopscience.iop.org/article/10.1149/2.0551915jes/pdf

Electroanalytical and Electrodeposited Simulation of Ce3+ in Molten LiCl-KCl

Porous silicon layers manufactured by using (100), 1-5 ohm·cm p-type (boron doped) wafer by electrochemical etching in HF etanol solution. Photoluminescence (PL) spectra of anodically etched silicon obtained for different conditions studied and surface characteristics are investigated by AFM. This study gives a simple way to determine specific surface are of porous silicon which plays a major role with porosity for explaining the blue shift in photoluminescence peak. Properties such as specific surface area, pore size, and pore size distribution, the main surface properties of layer are investigated from AFM data which are important material characteristics in many processing applications. The "specific surface area" (Sspecific) generally defined as the area of solid surface per unit mass of material, solid volume or cross section area. From 3-D reconstructions of AFM data, the surface area and the volume of the porous layer can be estimated directly and volume-surface specific area is calculated. For porous silicon this feature can be defined as the total surface area per volume and given by the unit m 2 /cm 3 . The method is simple not need to construct a special set up for measurement and non destructive.

/pdf/porous-silicon-volume-specific-surface-area-determination-1erjvrf56y.pdf

Porous Silicon: Volume-Specific Surface Area Determination from AFM Measurement Data

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An edge effect caused by a spontaneous bias on the anodizing current density at the edged area is found during electrochemical etching. On the porous silicon films formed by the electrochemical etching method, evidence of the edge effect appearing on the photoluminescence pattern is first proposed in the study. With an appropriate electrolytic cell design where a halo baffle is placed between the anode and cathode as a barrier to reactant flux on the outer ring, the flux at the edge would be curved. It results in various degrees of electrochemical reactions and various porous structures on the silicon wafer. The experimental results propose an exhaustive view at the edge area in electrochemical etching process, and also propose an optional selection for free-mask patterning technology of porous silicon.

Edge effect in electrochemical etching on porous silicon and its direct evidence on photoluminescence patterns

The electrolyte stirring method of anodization etch ing process for manufacturing porous silicon (PS) is re ported in this work. Two experimental setups of nature air stirring (PS- ASM) and electrolyte stirring (PS-ESM) are employed to clari fy the influence of stirring mechanisms on electrochemical etching proc ess. Compared to traditional fabrication without any stirring appara tus (PS-TM), a large plateau region of PS surface structure is obtained from samples with both stirring methods by the 3D-profiler measurement. Moreover, the light emission response is also improved by both pr oposed electrolyte stirring methods due to the cycling force in electr olyte could effectively enhance etch-carrier distribution while the electrochemical etching process is made. According to the analysis of statistical calculation of photoluminescence (PL) intensity, lo wer standard deviations are obtained from PS-samples with studied stirring methods, i.e. the uniformity of PL-intensity is effectively improved. The calculated deviations of PL-intensity are 93.2, 74. 5 and 64, respectively, for PS-TM, PS-ASM and PS-ESM.

/pdf/improvement-of-photoluminescence-uniformity-of-porous-3701j1ceu2.pdf

Improvement of Photoluminescence Uniformity of Porous Silicon by using Stirring Anodization Process

An investigation of the visible light glucose sensor by utilized nanoporous (NPS) silicon material as a sensitive layer was
proposed. In the experiments, all studied NPS films are prepared by electrochemical anodization technique and the
obtained depth are about 3.3 μm. The peak of PL-intensity curve is 610 nm under normal air condition. Based on its high
surface to volume ratio (SVR) and unique light emission properties, the studied NPS glucose sensor has a high
sensitivity and stability. The visible light response on the film surface switches obviously between distinct colors
with/without glucose treatment. As compared with conventional electronic glucose sensor, the highly sensitive and
obvious light switching characteristics would be important to related detection. It has a potential application on small-size,
low-cost, portable and electric-free sensor systems. After the immersion treatment of 1M glucose solution on the
studied NPS samples, an obvious blue-shift behavior of PL-feature (from 610 to 560 nm) is observed at room
temperature. The color switching can be read by a naked-eye easily.

The fabrication of glucose sensor by nanoporous silicon film and its switching characteristics on visible color light response

In this study, the thermal properties of silicon samples with surfaces of porous and geometrical formation were
reported. The etching methods of anodization chemical and heated KOH were utilized to perform the studied nano
porous silicon (NPS) and pyramidal, respectively. Compared with usual surface formation of ordinary silicon sample, the
larger surface to volume ratios were obtained from the fabricated NPS and pyramidal silicon devices. For the thermal
applications such as thermal sensor and microheater, the etching profiles and surface to volume ration of studied were
clarified by SEM measurement. Furthermore, the differential scanning calorimetry (DSC) was used to evaluate the
thermal dissipation properties of studied samples.

Meng-Kai Hsu

Papers

Edge effect in electrochemical etching on porous silicon and its direct evidence on photoluminescence patterns

Improvement of Photoluminescence Uniformity of Porous Silicon by using Stirring Anodization Process

The fabrication of glucose sensor by nanoporous silicon film and its switching characteristics on visible color light response

Thermal sensors based on nano porous silicon