(2) seems to indicate that the behaviour of the open circuit voltage is positive with temperature, but it is in fact dominated by the temperature dependence of the diode saturation current, which is given as(3)I0=BTγexp(EGkT)where B is an empirical factor which is temperature independent and dominated by material quality, γ is an empirical factor depending on the specific loss mechanism that is dominating in the cell and EG is the band gap of the cell.