Investigation and optical evaluation of precursors for the photodeposition of nanosized ZnS amorphous thin films

Abstract

Thin amorphous nanostructured ZnS films have been photochemically obtained by means of direct UV radiation (X= 254 nm) of the complex Zn [(CH 3)2CHCH2OCS2]2 deposited on Si(100) and on ITO glass through the spin-coating technique. The UV photolysis of thin films of Zinc Xanthate complex results in the loss of all ligands from the coordination sphere. The binding energy values for as-deposited films in X-Ray Photoelectron Spectra were 1022.7 eV for Zn2p3 and 163-169 eV for S 2p. The as-deposited film showed a non-uniform rough surface with a root-mean-square (rms) roughness of 48.5 nm and a maximum height, Rmax, of 460.5 nm. The annealed ZnS films showed a uniform and a reasonably light but smooth surface with a rms roughness of 43.0 nm and Rmax of 274.2 nm. The optical band gap was determined and found to be 3.2 ± 0.01 eV and 3.25 ± 0.01 eV. © 2007 Sociedad Chilena de Química.