feasibility of using CuMg alloy as back contact metal for n(+)-doped-layer free a-Si:H thin film solar cell (TFSC) has been investigated in this work. The ohmic-contact characteristic has been achieved by using the CuMg alloy as back contact metal. The proposed structure showed the typical solar cell current-voltage (I-V) characteristic. An initial efficiency of 4.3% has been obtained with a open-circuit voltage V-oc = 0.79 V. short-circuit current J(sc) = 13.4 mA/cm(2) and fill factor F.F. = 0.40. Furthermore, the experimental results also showed the CuMg alloy was suitable for the replacement of n(+)-doped-layer with the production cost reduction of a-Si:H TSFC. (C) 2011 Elsevier Ltd. All rights reserved.