الفهرس 
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Abstract
Nanocrystalline ZnS thin films were deposited by the
chemical bath deposition (CBD) technique on glass substrates from
an aqueous solution containing cadmium chloride, zinc chloride,
thiourea, ammonia and hudrazine. A parametric study (Influence of
the change in volume of reactants, temperature and pH level) of the
chemical bath deposition (CBD) technique has been done to get the
optimum conditions of depostion of ZnS thin films.
Analysis of differential scanning calorimetry pattern of the
as-deposited powder ZnS illustrated a crystallization peak at 350 °C.
X-ray diffraction studies have done on both powder and thin films
and revealed the nanocrystalline nature of both of them. Also, the
effect of annealing are studied.. The transmission micrographs of
the as-deposited and annealed ZnS thin films almost show the grains
which nearly around 3 nm which agree with the XRD results. The
scanning micrographs of the as-deposited ZnS thin films showed the
high compactness of these films, which are continuous and
homogeneous.
The optical properties of the as-deposited and annealed ZnS
thin films were investigated in the wavelength range 300-2500 nm
and the optical constants are calculated. The films showed a high
transmission more than 90%, a high refractive index 2.27 at 620 nm
and a wide band gap of 3.83 eV.
The resistivity of the as-deposited ZnS thin films (at 303 K)
decreases from 1.490 x 106 (Ω.cm) to 0.683 x 106 (Ω.cm) as the film
thickness increase from 97 nm to 304 nm. The resistivity of the ZnS
thin films was found to vary considerably with temperature. The
resistivity of the films reduced from ≈ 106 to ≈ 102 (Ω.cm), when the
temperature increased from 303 K to 473 K. Analysis of the
temperature dependence of the electrical conductivity, σDC, in the
temperature range 303 – 473 K during heating cycle has revealed
two linear regions. The activation energy for the two regions were
calculated.