Properties of CuInS2 thin films grown by a two-step process without H2S

CuInS2 thin films were prepared by sulfurization of sequentially deposited CuIn stacks with elemental sulfur. Precursors as well as reacted films are characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). Excess copper is required for optimum properties and leads to a CuS secondary phase segregated at the surface. Stoichiometry is regained by etching after which heterojunctions are formed by deposition of a CdSZnO window layer. An active area efficiency of 10.4% has been achieved.