The effect of annealing of ZnSe nanocrystal thin films in air atmosphere

The zinc selenide (ZnSe) nanocrystal thin films have been prepared on glass substrates by chemical bath deposition at 80 °C. The ZnSe films have been annealed in an air atmosphere at 373, 473, 573, 673 and 773 K for 1 h. The crystallographic structure and size of the crystallites, dislocation density, number of crystallites per unit surface area and strain have been studied by X-ray diffraction on as-deposited and annealed films. The surface morphology of ZnSe coated thin films obtained at different annealing temperatures has been elucidated by AFM studies. The optical properties of the films have been investigated by recording the transmission spectra. It has been observed that the energy band gap decreases upon annealing temperature. The conductivity measurements have been carried out using four probe methods. It is observed that the conductivity and activation energy change upon annealing temperature. (author)