Luminescent coupling effects in double-junction solar cells

We presented an analytical model which predicts a voltage enhancement in photocurrent-matched double-junction cells due to luminescent coupling between the two junctions. We demonstrated that the voltage increase between V_MPP to V_OC can be computed in terms of the luminescent coupling efficiency. Then we examined the model by simulation of a double-junction cell under different luminescent coupling efficiencies. We demonstrated that the upper limit of voltage enhancement in a double-junction cell between V_MPP to V_OC is 17.8 mV. The results demonstrate that the voltage enhancement increases with increasing the luminescent coupling efficiency, which consequently enhance the cell efficiency.