NANOPARTICLE PRECURSOR ROUTE TO LOW-TEMPERATURE SPRAY DEPOSITION OF CDTE THIN-FILMS

In this letter we report a nanoparticle-derived route to CdTe thin films. CdTe nanoparticles 39 +/- 8 Angstrom in diameter, prepared by an organometallic route, were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy. CdTe thin-film deposition was realized by spraying a nanoparticle/butanol colloid onto SnO2-coated glass substrates at variable susceptor temperatures. The resultant CdTe films were characterized by atomic force microscopy, x-ray diffraction, and UV-Vis spectroscopy. Smooth and dense CdTe thin films were obtained using growth temperatures similar to 200 degrees C less than conventional spray pyrolysis. A growth temperature dependence upon CdTe grain size formation and crystallinity was observed by atomic force microscopy and x-ray diffraction. UV-Vis characterization revealed a transformation in the optical properties of the CdTe thin films as a function of growth temperature. (C) 1995 American Institute of Physics.