Type

Conference Proceedings

Authors

M. Serantoni
Simon B. Newcomb
David Sutton
D. Noel Buckley
Colm O'Dwyer

Subjects

Engineering

Topics
anodic formation porous inp tem image cross section materials science koh electrolytes afm measurement electrochemistry

A mechanistic study of anodic formation of porous InP (2003)

Abstract When porous InP is anodically formed in KOH electrolytes, a thin layer ~40nm in thickness, close to the surface, appears to be unmodified. We haveinvestigated the earlier stages of the anodic formation of porous InP in 5mol dm-3 KOH. TEM clearly shows individual porous domains whichappear triangular in cross-section and square in plan view. The crosssectionsalso show that the domains are separated from the surface by a ~40nm thick, dense InP layer. It is concluded that the porous domains have asquare-based pyramidal shape and that each one develops from an individualsurface pit which forms a channel through this near-surface layer. Wesuggest that the pyramidal structure arises as a result of preferential porepropagation along the <100> directions. AFM measurements show that thedensity of surface pits increases with time. Each of these pits acts as asource for a pyramidal porous domain, and these domains eventually form acontinuous porous layer. This implies that the development of porousdomains beneath the surface is also progressive in nature. Evidence for thiswas seen in plan view TEM images. Merging of domains continues tooccur at potentials more anodic than the peak potential, where the current isobserved to decrease. When the domains grow, the current density increasescorrespondingly. Eventually, domains meet, the interface between theporous and bulk InP becomes relatively flat and its total effective surfacearea decreases resulting in a decrease in the current density. Quantitativemodels of this process are being developed.
Collections Ireland -> University College Cork -> Research Institutes and Centres
Ireland -> University College Cork -> Applied Nanoscience Group - Conference Items
Ireland -> University College Cork -> Tyndall National Institute
Ireland -> University College Cork -> Applied Nanoscience Group
Ireland -> University College Cork -> Chemistry
Ireland -> University College Cork -> College of Science, Engineering and Food Science
Ireland -> University College Cork -> Micro-Nanoelectronics Centre
Ireland -> University College Cork -> Chemistry - Conference Items

Full list of authors on original publication

M. Serantoni, Simon B. Newcomb, David Sutton, D. Noel Buckley, Colm O'Dwyer

Experts in our system

1
D. Noel Buckley
University College Cork
Total Publications: 27
 
2
Colm O'Dwyer
University College Cork
Total Publications: 121