Cathodic Deposition of CdTe from Aqueous Electrolytes

Abstract

CdTe of well-defined composition has been deposited cathodically from an aqueous solution of CdSo//4 and TeO//2. Films with a rest potention of less than minus 0. 3V vs. SCE are n-type, those with a rest potential greater than 0. 3V vs. SCE are p-type semiconductors. The rate of deposition increases with stirring rate; it is proportional to the TeO//2 concentration but independent of the CdSO//4 concentration. Films deposited at room temperature are amorphous, those deposited at higher temperatures are partly crystalline, the degree of crystallinity increasing the deposition temperature. Grain sizes are in the range 500-1000 Angstrom. Annealing at 350 degree C causes the crystallite size to increase to greater than equivalent to 0. 5 mu m. This work is of interest in the fabrication of large area solar cells.