Cdo Thin Film Lab Report

3.1 Film formation process

In the Nebulized Spray pyrolysis (NSP) method, starting materials required to form the desired semiconducting compound are in the form of solution, which were sprayed onto preheated glass substrates, resulting in the formation of thin films on the upper surface of the glass substrates according to the reaction specified earlier. The depositions were carried out according to the experimental procedure mentioned earlier. The quantity of reactive spices deposited depends on molarity of the precursor used, and volume of the solution sprayed. The samples were uniform, well adherent and yellowish in color[20,30].

3.2 X-ray diffraction pattern of CdO thin film The XRD pattern of CdO thin films prepared at

The graph is plotted having 4sinӨ along x-axis and βcosӨ along y-axis for the peaks of CdO with cubic phase. Consequently, the slope and y-intercept of the fitted time represent grain size and strain respectively.

Thickness of the thin film samples determined by stylus profilometer was found to increase upto 1.6 µm for a precursor solution volume of 20 ml and then decreased to 1.3 µm for a volume of 25 ml. The reason for the decrease may be due to peeling of the film with the agglomerated powdery deposits due to homogeneous reaction.

The number of crystallites per unit area (n) of the samples was found using the relation n= t / D3 (4)

Where D is the grain size and t is the thickness of the

The crystallite size associates with several physical parameters such as, substrate temperature, spray rate, pressure, growth atmosphere and concentration etc., it is difficult to relate crystallite size with different precursor solution volume [33]. The lattice constant ‘a’, volume ‘v’ and dislocation density ‘δ’ using the formulas, which were tabulated. 1/d2 = h2+k 2+l2 / a2 (5) v = a3 (6) δ = 1 /D2