Synthesis and characterization of aluminum-doped CdO thin films by sol-gel process

Aluminum-doped cadmium oxide (CdO:Al) thin films are deposited on glass substrates by the sol-gel dip-coating method, taking cadmium acetate dihydrate as the precursor material. Aluminum nitrate has been taken as a source of Al-dopant. XRD pattern reveals the good crystallinity of CdO thin films. SEM micrograph showed the presence of faceted crystallites. Optical study shows 40-85% transparency with a bandgap value lying in the range 2.76-2.52 eV, depending upon the Al content in the films. Optimum percentage of Al wits 5.22 for a maximum room temperature conductivity of 2.81 x 10(3) (Omega cm)(-1). Hall measurement confirmed that the material is of n-type, with mobility and carrier concentrations lying in the range 413-14.7 cm(2)/V s, and 3.4 x 10(19)-8.11 x 10(20) cm(-3), when percentage of Al varies in the range 1.32-7.24. (c) 2005 Published by Elsevier B.V.