1. The problem statement, all variables and given/known data The given quantities are the shunt resistances across each of the 3 diode junctions,assume them to be Rsh1,Rsh2,Rsh3; Tunnel diode resistances as Rt1 and Rt2, Photocurrent for each of the junction be Ip1,Ip2,Ip3 and bandgap of each subcell be Eg1,Eg2,Eg3 are given.Let V & I be the voltage and current across the complete triple junction cell. Now I need to find out (I-current) equation in terms of bandgap of each subcell and also it is a function of exponential terms(e^(function of V)) (diode current). I also need to find the voltage V interms of bandgap of subcells. 2. Relevant equations 3. The attempt at a solution I could get the current equation with the diode current( I=Is*e^(qVd/kT)) where Vd is the voltage across the diode (say for 1 subcell). The Vd is not given and I need to represent it interms of overall voltage V across the subcell.That is e^(function of V).