Effect of solar cell temperature on its performance is studied through the dependence of the solar cell’s parameters such as Isc (short circuit current) and Voc(open circuit voltage) on the cell temperature . The two –dimensional Laplace integral transform technique has been used to solve the heat diffusion equation for a solar cell subjected along the local day time to the incident global solar radiation. Mathematical expression for the temperature of the cell is obtained. As an illustrative example computations are carried out on a silicon solar cell at different operating conditions. The obtained results indicate that the increase in solar cell temperature make a degradation in its performance.