As q is the charge of electron, 1.6×10-19 C, A is diode ideality
factor, K is Boltzmann’s constant, 1.38×10-23 J/K, and TC is
the cell’s operating temperature in kelvin. The cell dark
saturation current, IS , varies with temperature according to
Equation (4). The photocurrent, Iph, is related to the cell’s
operating temperature and solar intensity as shown in
Equation (3).