Structural and optical properties of annealed CdO thin films prepared by spray pyrolysis

CdO films were prepared on glass substrates by the spray pyrolysis techniqu e. Results on structural, optical and electrical properties of the layers a s a function of the thermal annealing are reported. XRD data indicates that samples show microstructural perfection improvement as a function of annea ling time. The optical band-gap shows a dependence with the inverse of the squared crystallite size, suggesting that electron confinement is an import ant effect. The lattice parameter and band-gap energy of the samples anneal ed at 450 degreesC for 120 min correspond to the reported values of bulk Cd O crystals. In addition, the electrical resistivity measurement shows a sli ght decrease when annealing time is increased up to 40 min but it saturates for larger times. (C) 2001 Elsevier Science B.V, All rights reserved.