[1] Forschungszentrum Julich, IEF5 Photovolta, D-52425 Julich, Germany
[2] Univ Salford, Inst Mat Res, Salford M5 4WT, Lancs, England
[3] CVD Technol Ltd, Salford M5 4WT, Lancs, England
[4] Acad Sci Czech Republic, Inst Phys, CZ-16253 Prague, Czech Republic