Effect of the substrate nature on the structural properties of Cu/Te bi‐layers prepared by rf‐sputtering

Cu/Te bi-layers were deposited on glass, silicon (Si) single crystals, and on CdTe-coated glass substrates. The structural properties of these samples were investigated using grazing-incidence X-ray diffraction (GIXD). As-deposited samples showed various structural properties and phase formation depending on the nature of the substrate. Samples deposited on glass (amorphous substrate) did not reveal any crystallization on the surface layer, while those made on Si(111) and polycrystalline CdTe films showed Cu 2-x Te with a degree of crystallization depending on the substrate. Towards the volume, Cu 2-x Te was observed in all the samples with variable degrees of crystallization. Compound formation after annealing at 450 K was investigated. Particularly, Cu 2-x Te ↔ Cu 7 Te 5 phase transformations were observed in samples deposited on polycrystalline CdTe films after annealing at 450 K. The structural differences between the samples are correlated with the nature of the lattice in which both Cu and Te diffuse, which is more ordered in samples deposited on single crystal substrates and disordered in those made on amorphous substrates.