THIN-FILM CADMIUM MERCURY TELLURIDE PREPARED BY NONAQUEOUS ELECTRODEPOSITION

Using a new electrodeposition process, thin-film cadmium mercury telluride, CdxHg1-xTe, with (1 - x) no greater than 0.4, was electrodeposited onto an indium tin oxide-coated glass cathode. The deposition bath contained Cd(II), Hg(II), and tri-n-butyl phosphine telluride in propylene carbonate, and its composition was shown to have a direct effect on the composition of the electrodeposited films. Film composition was determined by atomic absorption spectroscopy and by proton-induced x-ray emission. Structural analysis of the cadmium mercury telluride films was achieved by way of scanning electron microscopy and x-ray diffractometry. Crystallinity of the films was shown to increase following heat-treatment in either argon or air. The bandgaps, which were determined by measuring the optical absorption spectra of these materials, were shown to decrease with increasing (1 - x), as predicted by an empirical expression.