Formation and characterization of Cu_xS layers on polyethylene film using the solutions of sulfur in carbon disulfide

摘要

Results of the formation of copper sulfide layers using the solutions of elemental sulfur in carbon disulfide as precursor for sulfurization are presented. Low density polyethylene film can be effectively sulfurized in the solutions of rhombic (α) sulfur in carbon disulfide. The concentration of sulfur in polyethylene increases with the increase of the temperature and concentration of sulfur solution in carbon disulfide and it little depends on the duration of sulfurization. Electrically conductive copper sulfide layers on polyethylene film were formed when sulfurized polyethylene was treated with the solution of copper (II/I) salts. Cu_xS layer with the lowest sheet resistance (11.2 Ω cm~(-2)) was formed when sulfurized polyethylene was treated with copper salts solution at 80℃. All samples with formed Cu_xS layers were characterized by X-ray photoelectron spectroscopy. XPS analysis of obtained layers showed that on the layer's surface and in the etched surface various compounds of copper, sulfur and oxygen are present: Cu2S, CuS, CuO, S8, CuSO4, Cu(OH)2 and water. The biggest amounts of CuSO4 and Cu(OH)2 are present on the layer's surface. Significantly more copper sulfides are found in the etched layers.