Characterization of CDTE-In co-sputtered films

CdTe-In films were grown on Coming glass substrates by means of the radio frequency sputtering deposition technique. The ternary alloys were produced by co-sputtering from a target containing CdTe and In. The In doping effect in CdTe is studied and the different kinds of compound materials that are formed when CdTe and In are mixed. Several kinds of materials are obtained depending on In concentration in the films and the substrate temperature during the deposition. The electrical and structural properties of the obtained materials are reported. The composition measurements by Auger electron spectroscopy show that In content in the films runs from 8 to 58 at.%, depending on the area fraction covered by the In piece glued onto the CdTe target. Low In concentration in the films grown at room temperature produces a low level of In doping in the CdTe cubic lattice. At higher In concentrations a crystalline structural transition to the CdTe hexagonal phase is observed in the films and then the formation of Cd-Te-In ternary structure is obtained. Ternary compound thin films of materials with composition on the pseudo-binary system CdTe-In2Te3 can be prepared by this growth technique at high substrate temperatures. (C) 1997 Elsevier Science Ltd.