Structural, Chemical and Optical Properties of the Polyethylene–copper Sulfide Composite Thin Films Synthesized Using Polythionic Acid as Sulfur Source
Applied Surface Science
Ancutiene, I.; Navea, J. G.; Baltrusaitis, J., Structural, chemical and optical properties of the polyethylene-copper sulfide composite thin films synthesized using polythionic acid as sulfur source. Appl. Surf. Sci. 2015, 347, 520-527.
Synthesis and properties of thin copper sulfide films deposited on polyethylene were explored for the development of low cost hybrid organic–inorganic photovoltaic materials. Polyethylene was used as a model organic host material for thin copper sulfide film formation. Adsorption–diffusion method was used which utilized consecutive exposure of polyethylene to polythionic acid followed by aqueous Cu(II/I) solution. Several crystalline copper sulfide phases were obtained in synthesized samples and elucidated using X-ray diffraction. Surface chemical composition determined using X-ray photoelectron spectroscopy showed the presence of copper sulfides in combination with copper hydroxide. Thickness of the composite material films ranged from several microns to ∼18 μm and depended on the Cu(II/I) exposure time. Bandgap of the materials obtained was measured and ranged from 1.88 to 1.17 eV. Importantly, heating these complex copper sulfide crystalline phase containing films at 100 °C in inert atmosphere invariably resulted in a single copper sulfide, anilite (Cu1.75S), phase. Anilite possesses a bandgap of 1.36 eV and has demonstrated excellent photovoltaic properties. Thus, the method described in this work can be used for a low cost large scale composite thin film photovoltaic material deposition based on anilite as photoactive material.
Copper sulfide, Anilite, Adsorption–diffusion, XRD, XPS