Fabrication and Characterization of Porous Silicon Nanowires

정대윤,조수경,문태호,손홍래 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.1

We report the synthesis of porous silicon nanowires through the metalassistedchemical etching of porous silicon in a solution of hydrofluoricacid and hydrogen peroxide. The morphology of porous siliconnanowires was characterized by scanning electron microscopy andtransmission electron microscopy. The etch rate of the porous siliconnanowires was faster than that of silicon nanowires, but slower than thatof porous silicon. The porous silicon nanowires distributed uniformly onthe entire porous silicon layer and the tips of the porous siliconnanowires congregated together. The single crystalline and sponge-likeporous structure with the pore diameters of less than 5 nm wasconfirmed for the porous silicon nanowires.

Effect of wafer resistivity and HF concentration on the formation of vertically aligned porous silicon

Yonughwan Lee,Jonghyuck Lee,Yonggun Shul,임상우 한국공업화학회 2008 Journal of Industrial and Engineering Chemistry Vol.14 No.1

In this study, the mechanism of vertically aligned porous silicon formation was examined. Silicon wafers with various resistivities and electrolytes containing different HF concentrations were used to explain porous silicon formation by the reaction at the silicon/electrolyte interface. Total pore volume increased proportionally to the current applied and anodization time. As the concentration of HF increased, pore depth and total pore volume formed in silicon anodization increased, then decreased beyond the optimum point. At a given applied current, total pore volume formed by anodization increased with an increase in resistivity of silicon wafer, but then decreased. From the mechanism of silicon etching and schematic isoetch contour of silicon suggested in this study, it is concluded that the formation of porous silicon is determined by an accumulation of F near the silicon/electrolyte interface in silicon anodization. # 2007 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Simply Modified Biosensor for the Detection of Human IgG Based on Protein AModified Porous Silicon Interferometer

Park, Jae-Hyun,Koh, Young-Dae,Ko, Young-Chun,Sohn, Hong-Lae Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.7

A biosensor has been developed based on induced wavelength shifts in the Fabry-Perot fringes in the visible reflection spectrum of appropriately derivatized thin films of porous silicon semiconductors. Porous silicon (PSi) was generated by an electrochemical etching of silicon wafer using two electrode configurations in aqueous ethanolic HF solution. Porous silicon displayed Fabry-Perot fringe patterns whose reflection maxima varied spatially across the porous silicon. The sensor system studied consisted of a mono layer of porous silicon modified with Protein A. The system was probed with various fragments of an aqueous Human Immunoglobin G (Ig G) analyte. The sensor operated by measurement of the Fabry-Perot fringes in the white light reflection spectrum from the porous silicon layer. Molecular binding was detected as a shift in wavelength of these fringes.

Well Defined One-Dimensional Photonic Crystal Templated by Rugate Porous Silicon

이성기 조선대학교 기초과학연구원 2013 조선자연과학논문집 Vol.6 No.3

Well defined 1-dimentional (1-D) photonic crystals of polystyrene replicas have been successfully obtained by removing the porous silicon from the free-standing rugate porous silicon/phenylmethylpolysiloxane composite film. Rugate porous silicon was prepared by an electrochemical etching of silicon wafer in HF/ethanol mixture solution. Exfoliated rugate porous silicon was obtained by an electropolishing condition. A composite of rugate porous silicon/phenylmethylpolysiloxane composite film was prepared by casting a toluene solution of phenylmethylpolysiloxane onto the top of rugate porous silicon film. After the removal of the template by chemical dissolution, the phenylmethylpolysiloxane castings replicate the photonic features and the nanostructure of the master. The photonic phenylmethylpolysiloxane replicas are robust and flexible 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.

Simply Modified Biosensor for the Detection of Human IgG Based on Protein AModified Porous Silicon Interferometer

Jaehyun Park,Youngdae Koh,손홍래,Young Chun Ko 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.7

A biosensor has been developed based on induced wavelength shifts in the Fabry-Perot fringes in the visible reflection spectrum of appropriately derivatized thin films of porous silicon semiconductors. Porous silicon (PSi) was generated by an electrochemical etching of silicon wafer using two electrode configurations in aqueous ethanolic HF solution. Porous silicon displayed Fabry-Perot fringe patterns whose reflection maxima varied spatially across the porous silicon. The sensor system studied consisted of a mono layer of porous silicon modified with Protein A. The system was probed with various fragments of an aqueous Human Immunoglobin G (Ig G) analyte. The sensor operated by measurement of the Fabry-Perot fringes in the white light reflection spectrum from the porous silicon layer. Molecular binding was detected as a shift in wavelength of these fringes.

고분자 복제 템플릿 방법을 이용하여 제조된 다공성 탄화규소의 미세구조 특성

이윤주,김수룡,김영희,신동근,원지연,권우택,Lee, Yoon Joo,Kim, Soo Ryong,Kim, Young Hee,Shin, Dong Geun,Won, Ji Yeon,Kwon, Woo Teck 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.6

Foam type porous silicon carbide ceramics were fabricated by a polymer replica method using polyurethane foam, carbon black, phenol resin, and silicon powder as raw materials. The influence of the C/Si mole ratio of the ceramic slurry and heat treatment temperature on the porous silicon carbide microstructure was investigated. To characterize the microstructure of porous silicon carbide ceramics, BET, bulk density, X-ray Powder Diffraction (XRD), and Scanning Electron Microscope (SEM) analyses were employed. The results revealed that the surface area of the porous silicon carbide ceramics decreases with increased heat treatment temperature and carbon content at the $2^{nd}$ heat treatment stage. The addition of carbon to the ceramic slurry, which was composed of phenol resin and silicon powder, enhanced the direct carbonization reaction of silicon. This is ascribed to a consequent decrease of the wetting angles of carbon to silicon with increasing heat treatment temperature.

Well Defined One-Dimensional Photonic Crystal Templated by Rugate Porous Silicon

Lee, Sung Gi The Basic Science Institute Chosun University 2013 조선자연과학논문집 Vol.6 No.3

Well defined 1-dimentional (1-D) photonic crystals of polystyrene replicas have been successfully obtained by removing the porous silicon from the free-standing rugate porous silicon/phenylmethylpolysiloxane composite film. Rugate porous silicon was prepared by an electrochemical etching of silicon wafer in HF/ethanol mixture solution. Exfoliated rugate porous silicon was obtained by an electropolishing condition. A composite of rugate porous silicon/phenylmethylpolysiloxane composite film was prepared by casting a toluene solution of phenylmethylpolysiloxane onto the top of rugate porous silicon film. After the removal of the template by chemical dissolution, the phenylmethylpolysiloxane castings replicate the photonic features and the nanostructure of the master. The photonic phenylmethylpolysiloxane replicas are robust and flexible 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.

pH 조건에 따른 기공성 실리콘의 나노구조 및 광학적 특성의 변화

김효한,조남희,Kim, Hyo-Han,Cho, Nam-Hee 한국세라믹학회 2013 한국세라믹학회지 Vol.50 No.4

The effect of chemical treatments of porous silicon in organic solvents on its nanostructural and optical features was investigated. When the porous Si was dipped in the organic solvent with various PH values, the morphological, chemical, and structural properties of the porous silicon was sensitively affected by the chemical conditions of the solvents. The size of silicon nanocrystallites in the porous silicon decreased from 5.4 to 3.1 nm with increasing pH values from 1 to 14. After the samples were dipped in the organic solvents, the Si-O-H bonding intensity was increased while that of Si-H bonding decreased. Photoluminescence peaks shifted to a shorter wavelength region in the range of 583 to 735 nm as the pH value increased. PL intensity was affected by the size as well as the volume fraction of the nanocrystalline silicon in the porous silicon.

Unified NCNT@rGO bounded porous silicon composite as an anode material for Lithium-ion batteries

NULUARUNAKUMARI,NULUVENUGOPAL,문지성,손근용 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.9

Nano/micro silicon particles were achieved by high energy ball milling of silicon mesh powder as a cheap and scalable process and used to make porous silicon by acid etching. Subsequent dispersing of porous silicon with nitrogendoped carbon nanotubes and graphene oxide followed by filtration and heat treatment gives the composite of unified structures of NCNT@rGO protected porous silicon. The obtained composite was studied as an anode material for Li-ion batteries, and it delivered a high reversible capacity of 862/861mAh g1 at 200 mA g1 with 91% of capacity retention. Along with superior rate capability, the prepared composite exhibited 578 and 451mAh g1 discharge capacity at 1,000 and 2,000mA g1 after a long 300 cycles. The enhanced electrochemical performance of the composite electrode can be accredited to the highly conductive and tough matrix of NCNT@rGO blend structures, and porosity in silicon effectively controls the silicon expansion and accommodates the required buffer volume during lithiation/de-lithiation.

Enhancement of Analyte Ionization in Desoprtion/Ionization on Porous Silicon (DIOS)-Mass Spectrometry(MS)

Lee Chang-Soo,Kim Eun-Mi,Lee Sang-Ho,KIm Min-Soo,Kim Yong-Kweon,Kim Byug-Gee The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.3

Desorption/ionization on silicon mass spectrometry (DIOS-MS) is a relatively new laser desorption/ionization technique for mass spectrometry without employing an organic matrix. This present study was carried to survey the experimental factors to improve the efficiency of DIOS-MS through electrochemical etching condition in structure and morphological properties of the porous silicon. The porous structure of silicon structure and its properties are crucial for the better performance of DIOS-MS and they can be controlled by the suitable selection of electrochemical conditions. The fabrication of porous silicon and ion signals on DIOS-MS were examined as a function of silicon orientation, etching time, etchant, current flux, irradiation, pore size, and pore depth. We have also examined the effect of pre- and post-etching conditions for their effect on DIOS-MS. Finally, we could optimize the electrochemical conditions for the efficient performance of DIOS-MS in the analysis of small molecule such as amino acid, drug and peptides without any unknown noise or fragmentation.