Control of the initial stage of the CdTe deposition was investigated by modifying the substrate and the source temperature profiles in close-spaced sublimation (CSS) process for improving the performance of CdTe thin film solar cells. In the modified temperature profile, the substrate temperature was increased with higher rate than that of the source temperature. By using the modified temperature profile, the conversion efficiency was improved as compared with the conventional temperature profile, and 15.3% efficiency( V-oc:0.811 V, J(sc): 26.3 mA/cm(2), FF: 0.718, 1 cm(2), AM 1.5) was achieved. (C) 2001 Elsevier Science B.V. All rights reserved.