Nanoscale ZnS and CdS thin films from single-source molecular precursors

In recent years, a great interest has been focused on II-VI semiconductor films for applications in different technological fields, with particular regard to optics and optoelectronics. In the present work the CVD (Chemical Vapor Deposition) technique was employed for the synthesis of ZnS and CdS nanocrystalline coatings. To this aim, O-isopropyl xanthates [M(O-iPrXan)2; M=Zn, Cd] were synthesised and used as single-source precursors. Film depositions were performed in N2 flow on silica substrates in a low pressure cold-wall CVD apparatus at temperatures between 200 and 450°C. Film crystallinity was studied by Glancing Incidence X-Ray Diffraction (GIXRD), while their chemical composition was analyzed by X-ray Photoelectron (XPS) and X-ray Excited Auger Electron (XE-AES) Spectroscopies. Their surface morphology was analyzed by Atomic Force Microscopy (AFM). Finally, the optical properties were investigated by UV-Vis absorption spectroscopy.