A Novel Sol-Gel Route To Pinhole-Free Iron Sulfide Thin Films

The general purpose of the study is to fabricate and improve upon FeS2 thin films which can be used as the photon absorber layer for a heterojunction or homojunction solar cell. This work deals with the preparation of the pyrite by an unconventional sol-gel approach. Thin pyrite films were prepared by sulfurizing the iron oxide films previously deposited through the sol-gel method using iron (III) chloride as a precursor. The structural, morphological, electronic and optical properties of the deposited films were determined using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, Auger electron spectroscopy (AES), UV-Vis absorption spectroscopy, Hall effect and profilometry. The effects of annealing and sulfurization temperatures were studied. The work was also devoted to the research of sodium diffusion from the substrate due to the thermal treatment and its affect on the pyrite films functionality

Growth and properties of Ti-Cu films with respect to plasma parameters in dual-magnetron sputtering discharges

Properties of different methods of magnetron sputtering (dc-MS, dual-MS and dual-HiPIMS) are studied and compared with respect to intermetallic Ti-Cu film formation. The quality and features of thin films are strongly influenced by the energy of incoming particles. The ion velocity distribution functions (IVDFs) were measured by time-resolved retarding field analyzer (RFA) in the substrate position. Thin films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD) and X-ray reflectometry (XR). Properties and crystallography of Ti-Cu films are discussed as a function of ion energy which is affected by the mode of sputtering. It was found that IVDFs measured in pulsed discharges exhibit double-peak distribution. The IVDFs reach the maximum at ion energies about  ~8 eV. The ion saturated current is highest in dual-HiPIMS discharge (~5 μA/cm2) and is mostly represented by Cu+ and Ar+ ions. The mode of sputtering influences chemical composition and film formation. The copper forms polycrystalline fcc-phase while much smaller Ti particles enwraps the copper crystallites or are part of a solid solution