Accession Number : ADA138601

Title :   X-Ray Photoelectron and Auger Electron Spectroscopic Study of the CdTe Surface Resulting from Various Surface Pretreatments: Correlation of Photoelectrochemical and Capacitance-Potential Behavior with Surface Chemical Composition.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY

Personal Author(s) : Ricco,A J ; White,H S ; Wrighton,M S

PDF Url : ADA138601

Report Date : 07 Feb 1984

Pagination or Media Count : 21

Abstract : The surface chemistry and stoichiometry of p- and n-type CdTe photoelectrodes treated with oxidizing and reducing etches have been characterized by X-ray photoelectron and Auger electron spectroscopies. The results of surface analysis have been correlated with the photoelectrochemical and capacitance-potential behavior of the photoelectrodes. 'Oxidized' surfaces are covered by a thin Te/TeO2 layer (or a thicker Te layer, if the etching procedure is slightly altered), resulting in Fermi level pinning: a constant photovoltage is found for a wide range of redox potentials and potential-independent space charge layer capacitance obtains. 'Reduced' surfaces closely resemble ion sputtered CdTe in chemical state and stoichiometry, resulting in more nearly ideal behavior: the semiconductor/electrolyte interface is rectifying in the dark; capacitance-potential behavior follows the Mott-Schottky equation near flat band conditions; and photovoltage varies with redox potential, from 0 to approx. 0.7 V for p-CdTe. (Author)

Descriptors :   *X ray photoelectron spectroscopy, *Auger electron spectroscopy, *Cadmium tellurides, *Photochemical reactions, *Electrochemistry, Surfaces, Surface chemistry, Chemical composition, Capacitance, Stoichiometry, P type semiconductors, N type semiconductors, Electrodes, Etching, Surface analysis, Tellurium, Oxides, Layers, Voltage, Oxidation reduction reactions

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE