Modeling of 1 eV dilute nitride multi-quantum well solar cell

The efficiency of existing In(Al)GaP/GaAs/Ge multi-junction solar cell can be further increased by the introduction of a 4^th junction with a band-gap in the range of 1 eV in between GaAs and Ge junctions. Dilute nitride (Ga(In)AsN) multi quantum wells (MQWs) inserted into the intrinsic region of a p-i-n GaAs are good candidates for this purpose. In this work, modeling has been done to estimate the feasibility of this structure. The result shows that the MQW 1 eV sub-cells could produce photocurrents greater than 18 mA/cm^-2 when operating in a tandem configuration behind a GaAs solar cell and thus can support 4-junction solar cells with 1 sun AM0 conversion efficiencies in the 40% range.