Profiled a-SiGe:H-buffer layers between the doped and the absorption layers of amorphous silicon germanium (a-SiGe:H) solar cells are routinely used to avoid bandgap discontinuities and high-defect densities at the p/i- and i/n interface. Here, we present a much simpler approach replacing the profiled a-SiGe:H-buffer layers at both interfaces by a-Si:H-buffer layers. It is demonstrated that for a-SiGe:H solar cells (thickness of the E(G)=1.5 eV part is 54 nm) these structures yield similar open circuit voltage V(OC) and fill factor (FF) compared to the bandgap profiled layer at the same short circuit current density j(SC). The influence of thickness, optical bandgap and position of the buffer layers on the solar cell performance is investigated. (C) 2002 Elsevier Science B.V. All rights reserved.