An investigation by AFM and TEM of the mechanism of anodic formation of nanoporosity in n-InP in KOH
Data(s) |
07/07/2016
07/07/2016
14/12/2006
29/11/2012
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Resumo |
The early stages of nanoporous layer formation, under anodic conditions in the absence of light, were investigated for n-type InP with a carrier concentration of ∼3× 1018 cm-3 in 5 mol dm-3 KOH and a mechanism for the process is proposed. At potentials less than ∼0.35 V, spectroscopic ellipsometry and transmission electron microscopy (TEM) showed a thin oxide film on the surface. Atomic force microscopy (AFM) of electrode surfaces showed no pitting below ∼0.35 V but clearly showed etch pit formation in the range 0.4-0.53 V. The density of surface pits increased with time in both linear potential sweep and constant potential reaching a constant value at a time corresponding approximately to the current peak in linear sweep voltammograms and current-time curves at constant potential. TEM clearly showed individual nanoporous domains separated from the surface by a dense ∼40 nm InP layer. It is concluded that each domain develops as a result of directionally preferential pore propagation from an individual surface pit which forms a channel through this near-surface layer. As they grow larger, domains meet, and the merging of multiple domains eventually leads to a continuous nanoporous sub-surface region. |
Formato |
application/pdf |
Identificador |
O'Dwyer, C., Buckley, D. N., Sutton, D., Serantoni, M. and Newcomb, S. B. (2007) 'An investigation by AFM and TEM of the mechanism of anodic formation of nanoporosity in n-InP in KOH', Journal of the Electrochemical Society, 154(2), pp. H78-H85. http://jes.ecsdl.org/content/154/2/H78.abstract 154 2 H78 H85 0013-4651 http://hdl.handle.net/10468/2833 10.1149/1.2401029 Journal of the Electrochemical Society |
Idioma(s) |
en |
Publicador |
Electrochemical Society |
Direitos |
© 2006 The Electrochemical Society. All rights reserved. |
Palavras-Chave | #Indium compounds #III-V semiconductors #Porous semiconductors #Nanoporous materials #Porosity #Electrochemical electrodes #Anodes #Atomic force microscopy #Transmission electron microscopy #Ellipsometry #Voltammetry (chemical analysis) #Carrier density #Etching #Surface structure |
Tipo |
Article (peer-reviewed) |