The AC parameters (cell capacitance and cell resistance) of Copper Indium Diselenide (CuInSe2) solar cell are measured using time-domain technique. The cell capacitance is calculated from the open circuit voltage decay (OCVD) and cell resistance with solar cell I-V characteristics measured in dark. The solar cell exhibits high parallel resistance and low parallel capacitance. The doping concentration and built in voltage are derived from the 1/C-P(2) versus bias voltage graph. The built-in voltage of the solar cell shows good agreement with measurements published in the literature. (C) 2004 Elsevier B.V. All rights reserved.