The semiconductor/electrolyte interface: A re-examination of n-type Cadmium Telluride electrodes

Abstract

The behavior of the n-CdTe electrode is re-examined for materials grown by the travelling heater method using Cd as a solvent. Except at pH 14, results appear to differ from those found with classical CdTe. Generally a large density of interface states exists in the potential range from −0.4 to −0.9 V, which leads to a Fermi level pinning process. The influence of redox species on this behavior is checked at pH 0 using oxygen and Fe 2+ Fe 3+ In the first case, a complex mechanism leads to a large density of interface states whereas in the second, the redox couple acts as a stabilizer for the electrode surface. From the point of view of material properties, photoelectrochemical measurements lead to conclude that these CdTe correspond to the best quality CdTe grown by more classical methods.