Preparation of CdTe coatings using the chemical deposition method

CdTe coatings have been prepared by the reaction between films of cadmium hydroxide deposited on glass and a solution prepared by the dissolution of tellurium in hydroxymethane sulfinic acid. The films of CdTe having thicknesses in the range of 1 μm have been deposited by immersing the cadmium hydroxide coatings in an alkaline solution containing a tellurium compound at 5°C, which is warmed to 70°C. Annealing at ca. 150°C for 24 h gives highly crystalline, cubic CdTe. The preparation of an aqueous solution containing tellurium, which remains stable, is essential for the success of the process. Conditions for the preparation of such a solution are described. Details for the preparation of thin films of Cd(OH)2 on glass, essential for the success of the process, are also described. The CdTe obtained was cubic, has a band gap energy of 1.51 eV, but does not display high photosensitivity.