The formation mechanism of gradient porous Si in a contactless electrochemical process
Affiliation
Univ Arizona, Chem & Environm EngnUniv Arizona, Mat Sci & Engn
Issue Date
2016
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ROYAL SOC CHEMISTRYCitation
The formation mechanism of gradient porous Si in a contactless electrochemical process 2016, 4 (19):4204 J. Mater. Chem. CJournal
JOURNAL OF MATERIALS CHEMISTRY CRights
CC-BY: This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Copyright is held by the author(s) or the publisher. If your intended use exceeds the permitted uses specified by the license, contact the publisher for more information.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Recently, gradient porous silicon has been developed to meet the requirements of various applications due to its unique physical and chemical properties. In this paper, the formation mechanism and morphology of radially symmetric gradient porous silicon films fabricated using a contactless method and their dependence on different process parameters, such as HF concentration, solution pH, current density and wafer resistivity, have been investigated in detail. The design and geometry of the sample assembly allow decreasing current density radially inward on the silicon surface in contact with HF based etchant solution. In the presence of surfactants, an increase in the distribution range of porosity, pore diameter and depth was observed by increasing HF concentration or lowering pH of the etchant solution, as the formation of pores was considered to be limited by the etch rates of silicon dioxide. Gradient porous silicon was also found to be successfully formulated both at high (10 mA cm2 ) and low (3 mA cm2 ) current densities. Interestingly, the morphological gradient was not developed when dimethyl sulfoxide (instead of surfactants) was used in the etchant solution potentially due to limitations in the availability of oxidizing species at the silicon–etchant solution interface.Note
Open access provided by RSC Gold Voucher.ISSN
2050-75262050-7534
Version
Final published versionAdditional Links
http://xlink.rsc.org/?DOI=C6TC00309Eae974a485f413a2113503eed53cd6c53
10.1039/C6TC00309E
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Except where otherwise noted, this item's license is described as CC-BY: This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Copyright is held by the author(s) or the publisher. If your intended use exceeds the permitted uses specified by the license, contact the publisher for more information.