Post-selenization of stacked precursor layers for CIGS

In this study the possibility of the fabrication of CIGS layers from stacked precursors with selenization is examined. Different sequences of precursor layers and two different selenization methods were applied, in order to establish the optimal order of Cu, In and Ga layers in the precursor layer stack. The obtained CIGS films were studied by different micro- and surface analysis methods (TEM, SEM, EDS, XRD, SNMS, XPS). Since the evaporation of a Se layer and post-annealing does not result in a homogeneous CIGS layer, the appropriate selenization must be accomplished in Se-vapour. ► The fabrication of CIGS with selenization of stacked precursors was examined. ► Different sequences of precursor layers and selenization methods were applied. ► The appropriate selenization must be completed in Se-vapour. ► The optimum sequence of the precursors is: In, Ga, Cu. ► The reason for this is the diffusion properties of the precursor materials.