The optimization of high indium and high phosphorus content InGaAs/GaAsP strained layer superlattices for use in multijunction solar cells

InGaAs/GaAsP strained layer superlattices (SLS) with high phosphorus and high indium content inserted into the intrinsic region of GaAs solar cells increases short circuit current with minimal impact on open circuit voltage. Very thin, high phosphorus content barriers provide several key advantages over other methods, namely 1) thin barriers occupy less space in a depletion width-limited SLS, 2) carrier transport is primarily due to tunneling, and 3) the height of the barrier, or depth of the well, is not subject to thermionic emission requirements. Our staggered well concept reduces quantum size effects to increase absorption beyond the GaAs band edge.