The application of periodic light grating couplers as an alternative to randomly textured transparent conductive oxides was investigated by using patterned aluminium doped zinc oxide (ZnO:Al) as a front contact. The periods and groove depths of the gratings were adjusted independently from each other and vary between 1-4 mum and 100-600 nm, respectively. We have analysed the optical properties of the gratings and the optoelectronic properties of microcrystalline silicon thin-film solar cells with integrated grating couplers. To benchmark the achieved results, the performance of the solar cells is discussed in comparison to the cells deposited on flat and randomly textured substrates. (C) 2003 Elsevier B.V. All rights reserved.