Oriented cadmium oxide thin solid films

A chemical bath deposition technique has been developed for the preparation of Cd(O-2)(0.88)(OH)(0.24) thin films on glass and quartz substrates from alkaline media at room temperature. These films were then annealed at 473 K in order to obtain cadmium oxide films. Two baths were used for him preparation. X-Ray diffraction analysis clearly showed that the CdO films obtained from a bath without KBr have a preferred crystalline orientation in the [200] direction while those obtained from a bath containing KBr had only slightly preferred crystalline orientation in the [111] direction. The optical bandgap, E(g), was evaluated from the VIS absorption spectra. It was found that E(g) for the films oriented in the [200] direction is 2.63 eV,while it is 2.57 eV for those with the slight [111] orientation. The different values of the cross-over terminal points of absorption and transmittance spectra confirm the difference between the films with different crystalline orientation.