Structural, chemical and luminescent investigation of MBE- and CSS-deposited CdTe thin-films for solar cells

In this study we combine scanning electron microscopy (SEM)-based cathodoluminescence (CL) spectrum imaging and electron backscatter diffraction (EBSD) in order to map the spatial distribution of various atomic-level defects in CdTe films as a function of deposition and film processing. Two different deposition techniques were used. Lattice-matched, epitaxial CdTe films were deposited on a single crystal as well as on polycrystalline CdTe substrates by molecular beam epitaxy (MBE). For comparison purposes, polycrystalline CdTe films were deposited using our standard close-spaced sublimation (CSS) method on glass-based substrates.