PREPARATION OF OPTICAL-QUALITY ZNCDTE THIN-FILMS BY VACUUM EVAPORATION

A procedure to make optical quality thin films of ZnxCd1-xTe by use of vacuum evaporation of the ternary compound has been developed. The st arting point was the preparation of the compound that was then used as the source in a simple vacuum evaporation system. The characteristics of a film containing 85% ZnTe (x = 0.85) are presented. Electron micr oscope, atomic force microscope, x-ray and optical spectral measuremen ts were made. The index of refraction was determined at room temperatu re from transmittance measurements in the range of from 580 to 800 nn and was found to agree within 1% with values found by others for singl e crystals. We did this by assuming a Sellmeier equation and a known i ndex of refraction at infinite wavelength. The calculation also yielde d the roughness of the film. (C) 1998 Optical Society of America.