Metalorganic vapor phase epitaxy growth of dual junction solar cell with InGaAs/GaAsP superlattice on Ge

Abstract

The impact of growth temperature was investigated on the quality and interface abruptness of InGaAs/GaAsP multiple quantum wells (MQWs) grown on various misoriented substrates. The growth of MQWs on substrates with a larger misoriented angle required a lower temperature. Non-radiative carrier lifetimes in MQWs strongly depended on the quality and abruptness of MQWs. On the basis of this understanding, a dual junction cell consisting of InGaAs/GaAsP superlattice top cell and Ge bottom cell was successfully fabricated. The result encourages the application of InGaAs/GaAsP superlattice for better current balancing and higher efficiency by III-V/Ge multiple junction solar cells.