The effects of surface energetics on the cyclic voltammetry of metallocenes at nonilluminated n-InP electrodes

Journal Article · Thu Oct 31 23:00:00 EST 1985 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2113641· OSTI ID:6093267

Koval, C A; Austermann, R L

Electron transfer processes at n-type InP electrodes of moderate to low doping density were investigated by monitoring the cyclic voltammetric dark currents of a series of metallocenes in acetonitrile solutions. The formal reduction potentials of the metallocenes span the bandgap of InP, allowing a comparison of the cyclic voltammetric response as a function of the formal reduction potential and the energetic condition of the electrode surface. The energetic condition of the electrode surface during the cyclic voltammetry experiments was monitored by measurements of the capacitance of the space charge region. A simple chemical etching and electrochemical cycling procedure yielded reproducible surface energetics. The n-InP/acetonitrile interface in the depletion condition responded ideally to changes in electrode potential, as evidenced by linear Mott-Schottky plots, over a range of about 0.9V. It was possible to achieve an accumulation condition at negative potentials, but the interface could not be inverted at positive potentials. The n-InP/acetonitrile interface is less susceptible to surface oxidation than is the p-InP/acetonitrile interface. For each metallocene +1/0 couple, the reversibility of cyclic voltammetric (CV) waves at n-InP was dependent on the doping density of the electrode (N /SUB D/ ) and the proximity of the formal reduction potential (E/sup 07/) to the conduction bandedge (E /SUB CB/ ). Couples with E/sup 07/ located negative of E /SUB CB/ displayed nearly reversible CV waves. Couples with E/sup 07/ located in the bandga were reduced irreversibly at overvoltages of 400-500 mV. A couple with E/sup 07/ located slightly positive of E /SUB CB/ yielded a partially reversible CV wave at moderate N /SUB D/ , but the wave became irreversible at low N /SUB D/ . Oxidation of couples with E/sup 07/ positive of -0.5V vs. E/sup 07/ for ferricenium/ferrocene was not observed.

• Research Organization: Department of Chemistry, University of Colorado, Boulder, CO
• OSTI ID: 6093267
• Journal Information: J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 132:11; ISSN JESOA
• Country of Publication: United States
• Language: English

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ACETONITRILE
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DIENES
ELECTROCHEMISTRY
ELECTRODES
ELECTRON TRANSFER
ENERGY SPECTRA
FERROCENE
FUNCTIONS
HYDROCARBONS
INDIUM COMPOUNDS
INDIUM PHOSPHIDES
IRON COMPLEXES
MATERIALS
N-TYPE CONDUCTORS
NITRILES
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ORGANIC NITROGEN COMPOUNDS
OVERVOLTAGE
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PNICTIDES
POLYENES
REDOX POTENTIAL
REDUCTION
RESPONSE FUNCTIONS
SEMICONDUCTOR MATERIALS
SPECTRA
SURFACE PROPERTIES
TRANSITION ELEMENT COMPLEXES
VOLTAMETRY