Impedance porous silicon

Although the dissolution process results in the formation of a porous structure, electrode impedance measurements [72, 73] have shown that the etching process is not limited by mass transport, even for thick porous silicon layers [74]. Figure 12 shows a plot of potential as a function of time during pore formation in p-Si(lOO),... 

V. P. Parkhutik, E. S. Matveeva, and R. Diaz Calleja, Impedance study of aging porous silicon films, Electrochim. Acta 41(7/8), 1313, 1996. 

Commonly used spectroscopic or analytical techniques for characterizing surfaces and coating layers on porous silicon are Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, energy dispersive X-ray spectrometry, fluorescence spectroscopy, UV-Vis absorption/reflectance spectroscopy, thin film optical interference spectroscopy, impedance spectroscopy, optical microscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, ellipsometry, nitrogen adsorption/desorp-tion analysis, and water contact angle. 

Koshida N, Nagasu M, Sakusabe T, Kiuchi Y (1985) The current voltage characteristics of a photoelectrochemical cell using p-type porous silicon. J Electrochem Soc 132(2) 346-349 Koshida N, Nagasu M, Echizenya K, Kiuchi Y (1986) Impedance spectra of p-type porous Si-electrolyte interfaces. J Electrochem Soc 133(11) 2283-2287 Mamykin AI, Moshnikov VA, Ilin AY (1998) Magnetic resonance spectroscopy of porous quantum-size structures. Semiconductors 32(3) 322-324... 

Yarkin DG (2003) Impedance of humidity sensitive metal/porous silicon/n-Si structures. Sens Actuators A 107 1-6 Yeh Y, Tseng T, Chang D (1989) Electrical properties of porous titania ceramic humidity sensors. J Am Ceram Soc 72 1472-1475... 

Isothermal Infiltration. Several infiltration procedures have been developed, which are shown schematically in Fig. 5.15.P3] In isothermal infiltration (5.15a), the gases surround the porous substrate and enter by diffusion. The concentration of reactants is higher toward the outside of the porous substrate, and deposition occurs preferentially in the outer portions forming a skin which impedes further infiltration. It is often necessary to interrupt the process and remove the skin by machining so that the interior of the substrate may be densified. In spite of this limitation, isothermal infiltration is used widely because it lends itself well to simultaneous processing of a great number of parts in large furnaces. It is used for the fabrication of carbon-carbon composites for aircraft brakes and silicon carbide composites for aerospace applications (see Ch. 19). 

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