Simulation study of multijunction solar cell incorporating GaAsBi

This work is concerned with a novel four junction III-V bismide multijunction solar cell, where GaInP
₂
is used as the top layer, GaAs as second layer, a 1eV band-gap GaAs
_0.94
Bi
_0.0583
as third layer and 0.7eV GaAs.
₉₁
Bi.
₀₈₅₇
as bottom layer. To produce optical transparency and maximum current conductivity through top and bottom cells, it has been considered that these four sub-layers are lattice matched and series connected. Investigating the semiconducting characteristics of GaInP
₂
, GaAs, GaAs
_0.94
Bi
_0.0583
and GaAs
_0.91
Bi
_0.0857
, the theoretical photo-conversion efficiencies for this four junction solar cell have been calculated to be 52.2% at air mass global (AM1.5G) and 56.7% at air mass direct normal (AM1.5D) under 1 sun condition by using a modified version of spectral p-n junction model.