The temperature functional dependence of the solar cell efficiency is studied without neglecting (dI(sc)/dT). The temperature dependent parameters that determine the value of the short circuit current I-sc are considered I-sc is also given as a function of the incident solar irradiance. The variation of the efficiency with temperature along the local day time is also evaluated. The conditions governing the sign of (dV(oc)/dT) are indicated an illustrative example for a silicon cell is given.