Screen printed conductive CuS-poly(acrylic acid) composite coatings

Copper sulfide (CuS) powder precipitated from two different chemical baths (citrate and triethanolamine baths) was dispersed in a poly(acrylic acid) aqueous solution and the resulting mixtures were screen-printed over glass slides. Compared to the coatings of the same composite materials obtained by casting, the screen-printed coatings show better homogeneity and an improved thermal stability (up to 300°C). Sheet resistances of 50 Ω/□ were typical in 20 μm thick coatings and these values remained stable even after baking in nitrogen or vacuum at 200–300°C. The X-ray diffraction pattern indicates degradation of CuS to Cu_1.8S and Cu_1.96S, particularly in air-baked samples at 250–300°C. The XRD, TGA and R_□ results show CuS(Cit)–PAA samples as superior conductive coatings.