FORMATION OF CADMIUM SULFIDE (CdS) NANOFILM ON A Cd(OH)2/SiO2 PRECURSOR LAYER
A. S. Vorokh, N. S. Kozhevnikova, A. A. Rempel, A. Magerl
Keywords: cadmium sulfide, chemical deposition, nanostructured films
Pages: 1206-1210
Abstract
Dense thin nanostructured films of cadmium sulfide CdS obtained by chemical deposition from aqueous solutions are strongly bound to a substrate due to the formation of cadmium hydroxide Cd(OH)2 in the system. By X-ray reflectometry and grazing incidence diffraction it is found that at the beginning of the deposition a dense Cd(OH)2/SiO2 layer is produced on the surface of a silicon or glass substrate. This layer is formed through the atomic-layer adsorption of crystalline 1-3 nm thick Cd(OH)2 film by the oxygen-containing substrate surface. During sulfidation of this cadmium-containing substrate layer, a surface nucleation layer of CdS/Cd(OH)2/SiO2 forms, which provides the growth, denseness, and strong adhesion to the substrate of nanostructured CdS film with a disordered structure. According to the obtained experimental data, a "hydroxide scheme" of film deposition is confirmed and refined, and the stages of CdS nanofilm formation are determined.
|
