Thickness dependence of microcrystalline silicon solar cell properties

This paper addresses the performance of pin and nip solar cells with microcrystalline silicon (muc-Si:H) absorber layers of different thickness. Despite the reverse deposition sequence, the behavior of both types of solar cells is found to be similar. Thicker absorber layers yield higher short-circuit currents, which can be fully attributed to an enhanced optical absorption. Open-circuit voltage V-OC and fill factor FF decrease with increasing thickness, showing limitations of the bulk material. As a result of these two contrary effects the efficiency II varies only weakly for absorber layers of similar to 1 to - 4 mum thickness, yielding maximum values up to 8.1 %. For a-Si:H/muc-Si:H stacked solar cells an initial efficiency of 12% has been obtained. (C) 2001 Elsevier Science B.V. All rights reserved.