Cu(In(0.52)Ga(0.48))Se(2) solar cell performance with an MBE-grown ZnS buffer layer was studied. It was found that cell performance with the ZnS buffer layer was inferior compared to that with the US buffer layer; however, by insertion of a 50 nm US layer in addition to the ZnS buffer layer, the device performance was improved and was better than that with the US buffer layer. The higher device performance by using the ZnS/CdS double buffer layer may be due to the improved interface properties of the device. (C) 2008 Elsevier B.V. All rights reserved.