ZnO layers deposited by Atomic Layer Deposition

The structure of 40 nm thick epitaxial ZnO layers grown on single crystalline sapphire and GaN substrates by atomic layer deposition has been studied using transmission electron microscopy. The growth is carried out between 150°C and 300°C without any buffer layer using di-ethyl zinc and water precursors. The ZnO layer on sapphire is found to be polycrystalline, which is probably due to the large misfit (~15 %) and the relatively low deposition temperature. However, the small misfit (~1.8 %) between the ZnO layer that is deposited on GaN at 300°C resulted in a high quality single crystalline layer

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