It　is　well　known　that　conventional　GaInP/GaInAs/Ge　three-junction　(3J)　solar　cells　are　difficult　to　continue　to　ascend　when　the　efficiencies　reach　32%　and　42%　under　AM0　and　AM1.5D　concentrated,　respectively.　In　AlGaInP/AlGaInAs/GaInAs/GaInNAs/Ge　five-junction　(5J)　solar　cells,　the　performance　of　the　AlGaInP,　AlGaInAs　and　GaInNAs　sub　cell　is　the　key　factor　for　conversion　efficiency　of　the　5J　solar　cell.　We　investigate　the　AlGaInP/AlGaInAs/Ge　3J　solar　cell.　By　incorporating　surfactant　trimthylantimony　into　the　AlGaInP　material,　the　crystal　quality　of　AlGaInP　is　improved　and　the　spectrum　absorption　range　of　AlGaInAs　is　extended.　The　current　density　of　each　sub　cell　exceeds　11.3mA/cm　2　as　is　desired.　Then　we　apply　this　3J　structure　to　grow　the　lattice-matched　5J　solar　cell　and　obtain　the　short　circuit　current　of　134.96　mA,　open　circuit　voltage　of　4399.6　mV,　fill　factor　of　81.7%　and　conversion　efficiency　of　29.87%.