Anodic behavior of InP: film growth, porous structures and current oscillations.

Buckley, D. Noel; O'Dwyer, Colm; Harvey, E.; Melly, T.; Sutton, David; Newcomb, Simon B.

Anodic behavior of InP: film growth, porous structures and current oscillations.

Files

PARIS_INVITED_PV_SPR_2003_F.PDF(1.38 MB)

Accepted Version

Date

2003-04

Authors

Buckley, D. Noel

O'Dwyer, Colm

Harvey, E.

Melly, T.

Sutton, David

Newcomb, Simon B.

Publisher

Electrochemical Society

Abstract

We review our recent work on the anodization of InP in KOH electrolytes. The anodic oxidation processes are shown to be remarkably different in different concentrations of KOH. Anodization in 2 - 5 mol dm-3 KOH electrolytes results in the formation of porous InP layers but, under similar conditions in a 1 mol dm-3 KOH, no porous structure is evident. Rather, the InP electrode is covered with a thin, compact surface film at lower potentials and, at higher potentials, a highly porous surface film is formed which cracks on drying. Anodization of electrodes in 2 - 5 mol dm-3 KOH results in the formation of porous InP under both potential sweep and constant potential conditions. The porosity is estimated at ~65%. A thin layer (~ 30 nm) close to the surface appears to be unmodified. It is observed that this dense, near-surface layer is penetrated by a low density of pores which appear to connected it to the electrolyte. Well-defined oscillations are observed when InP is anodized in both the KOH and (NH4)2S. The charge per cycle remains constant at 0.32 C cm-2 in (NH4)2S but increases linearly with potential in KOH. Although the characteristics of the oscillations in the two systems differ, both show reproducible and well-behaved values of charge per cycle.

Keywords

KOH electrolytes , Anodic formation , Transmission electron microscopy , Anodization , Anodic oxidation , Oscillatory behavior

Citation

Buckley, D. N., O’Dwyer, C., Harvey, E., Melly, T., Sutton, D. and Newcomb, S. B. (2003) 'Anodic behavior of InP: film growth, porous structures and current oscillations', State-of-the-Art Program on Compound Semiconductors (SOTAPOCS XXXVIII) and Wide-Bandgap Semiconductors for Photonic and Electronic Devices and Sensors III, 203rd ECS Meeting, Palais des Congres de Paris, France, 27 April - 2 May. Proceedings - Electrochemical Society, Vol. 4, pp. 48-62. ISBN 1-56677-349-0.