Nanoparticle precursor route to low-temperature spray deposition of CdTe thin films

Abstract

In this letter we report a nanoparticle‐derived route to CdTe thin films. CdTe nanoparticles 39±8 Å 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 ∼200 °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.