Analysis Of Spray Pyrolysis

Spray pyrolysis is basically a thermal reaction between clusters of the liquid/vapor-atoms of different chemical species. The spray pyrolysis technique involves spraying of aqueous solution in spray form containing a decomposable salt solution of the constituent atoms. The experimental setup used in the present study is described elsewhere [21]. CdO thin films with different Cr- doping concentrations were deposited on ultrasonically cleaned microscopic glass substrates. The appropriate quantity of cadmium acetate dihydrate {(CH3 COO)2 •Cd•2H2O} was measured to make a 0.05 M solution by dissolving in 50 ml of deionised water and methanol in 1: 1 ration. The required amount of Chromium trichloride hexahydrate (CrCl3 • 6H2O), depending on the desired doping concentrations (0.25 wt. %, 0.50 wt. %, 0.75 wt. %, and 1.0 wt. %) was mixed with precursor solution. The resulting solution was sprayed on the glass substrates preheated to 300 ˚C. Chromel–alumel thermocouple was used to measure the substrate temperature, by placing at the center of the hot plate using a digital INDFUR PID …show more content…
2 as a function of Cr- doping concentration. Figure 2a shows the surface microstructure of the undoped CdO thin films, which consists of uniformly distributed spherical shaped grains throughout the surface along with small patches of particles and some agglomeration. The Figs. 2b-e show the surface microstructures from the films doped with 0.25 wt. %, 0.50 wt. %, 0.75 wt. %, and 1.0 wt. % of Cr- doping concentrations, respectively. Figure 2b seems to be the distribution of grains is uniform with regular shapes and sizes. The films doped with 0.50 wt. % of Cr (Fig. 2c) show a uniform surface microstructure having some porous with voids. Improved grain size and enhanced surface uniformity were observed in the films doped with 0.75 wt. % Cr (Fig. 2d). Fig 2e shows the uniformly distributed spherical shape