The AC parameters of Gallium Arsenide (GaAs/Ge) solar cell were measured at different cell temperatures (198-348 K) by varying the cell bias voltage (forward and reverse) under dark condition using impedance spectroscopy technique. It was found that the cell capacitance increases with the cell temperature where as the cell resistance decreases, at any bias voltage. The measured cell parameters were used to calculate the intrinsic concentration of electron-hole pair, cell material relative permittivity and its band gap energy. The diode factor and the cell dynamic resistance at the corresponding maximum power point decrease with the cell temperature. (C) 2002 Elsevier Science B.V. All rights reserved.