The influence of the InGaP window layer on the optical and electrical performance of GaAs solar cells

A wide band gap heterolayer is usually added to the front face of GaAs and other III-V solar cells to favour transparency and to passivate the emitter. This extra front layer influences the optical behaviour of the device and therefore must be taken into account in the optimization of the antireflection (AR) coating. A set of AR layers was optimized with respect to their thicknesses for an InGaP front layer in GaAs solar cells. Complementary, numerical simulation of the whole device was performed using the D-AMPS code. Our results confirm the importance of surface passivation and demonstrate that the thickness of 30 nm usually proposed for this window layer is not the optimal.