Parameter extraction can be used as a tool to determine the optimum chalcogenization condition of the absorber layer in manufacturing thin film solar cells. In this paper, CuIn(Se1-y,S-y)(2) solar cells fabricated at different selenization conditions using a two-step process were characterized. Device and performance parameters of the solar cells were deter-mined from the current density-voltage (J-V) characteristics of the devices. The J-V curves were analyzed using the two-diode solar cell model. Devices selenized for 40-60 min exhibit relatively low series and shunt resistances, low fill factor and conversion efficiency. Better performance was observed for solar cells with absorber layer selenized for 10 to 20 min. (C) 2008 Elsevier B.V. All rights reserved.