Phase pure deposition of flower-like thin films by aerosol assisted chemical vapor deposition and solvent mediated structural transformation in copper sulfide nanostructures

Bis(O-isobutyldithiocarbonato)copper(II) complex [Cu(SCSOCH₂CH(CH₃)₂)₂] was used as a single source precursor to synthesize both copper sulfide thin films and nanoparticles. The copper sulfide thin films were deposited by the aerosol assisted chemical vapor deposition method, whereas the nanoparticles were synthesized by the hot injection route. The deposited copper sulfide thin films showed different morphologies based on spherical to flower or flakes-like crystallites depending on the temperature of deposition. Powder X-ray diffraction studies of the deposited films revealed formation of pure Covellite-hexagonal phase of copper sulfide, with high crystallinity at elevated temperature. The diffraction pattern of nanoparticles synthesized in dodecanthiol, and 1-octadecene at 150 °C, 190 °C and 230 °C showed the formation of monodispersed nanoparticles of Cu_1.78S Roxbyite phase with an average size of ca. 12 ± 1 nm. Interestingly, when oleylamine was used as a capping solvent, the formation of Covellite and Digenite phases were obtained at temperatures of 110 °C and 190 °C respectively. Electron microscopic studies showed formation of rod shaped particles at 110 and 150 °C, whereas at higher temperatures formation of fairly spherical nanoparticles were observed.