Variation of resistivity of copper-doped cadmium telluride prepared by electrodeposition

Thin film p-cadmium telluride that has been electrodeposited from non-aqueous propylene carbonate has been doped with copper using two electrochemical methods. The first involved electrochemical codeposition (in situ doping) of copper and cadmium telluride, and the second employed electromigration of copper into thin film cadmium telluride that had been annealed. After the film was removed from the conductive substrate, the resistivity of the resultant film was determined by either two- or four-strip methods, depending on the resistance of the film. To avoid current leakage by way of surface moisture, the film resistivity was measured under vacuum. The temperature dependence of the resistivity was determined for both doped and undoped films, and activation energies were obtained. As the copper density was increased, the resistivity and activation energy decreased. A Hall effect measurement of highly doped film revealed that the carrier density is substantially less than the estimated copper density, indicating segregation of part of the copper into grain boundaries of the polycrystalline film. Similar behaviour has been observed for other polycrystalline thin films. The effect of copper density and mobility are affected by grain boundary states. © 1990 IOP Publishing Ltd.

Duke Scholars

Author Jesko Von Windheim Environmental Sciences and Policy