Material investigation on magnetron sputtered $\text{TiO}_{2-x}$ alternative buffer layers for CIGSe absorber produced in an industrial roll-to-roll hybrid sputter co-evaporation process

In this work, material investigation with focus on surface characterization of magnetron sputtered titanium dioxide from titanium doped ceramic targets as buffer layer are performed. The aim is to predict suitability for CIGSe absorber produced in a semi-industrial, roll-to-roll hybrid sputter co-evaporation process with certain peculiarities in CIGSe growth. Additionally, current used alternative buffer materials such as zinc oxy-sulfide or zinc magnesium oxide deposited by magnetron sputtering are included in the present examination. A potential way to manipulate band positions of TiO 2 by controlling the concentration of oxygen vacancies is investigated by photoelectron spectroscopy and UV-VIS spectroscopy.