Copper sulfides obtained by spray pyrolysis — Possible absorbers in solid-state solar cells

Copper sulfide (CuxS, x = 1.8–2) thin films were deposited at 285 °C by spray pyrolysis from aqueous and alcoholic solutions of copper (II) chloride and thiourea with different Cu:S molar ratio. The XRD analysis showed that deposited films are chemically close to chalcocite (Cu2S) or to mixtures of copper-rich phases (Cu2S, Cu1.8S, Cu1.9375S) in which chalcocite or digenite (Cu1.8S) is predominant. The films containing the single phase Cu2S are denser and more homogenous than the films formed by two or more phases. The current–voltage (I–V) dark curves showed the diode behavior of the films, depending on the film thickness.