Lightweight, low cost InGaP/GaAs dual-junction solar cells on 100 mm epitaxial liftoff (ELO) wafers

InGaP/GaAs dual junction (DJ) solar cells were fabricated on epitaxial liftoff (ELO) 100 mm diameter GaAs wafers. These ELO DJ cell wafers have total semiconductor thickness less than 5 ¿m and weigh less than 1.7 g. The best solar cells exhibited an efficiency of 28.69% at one sun AM1.5D illumination, which is the highest reported efficiency for DJ ELO thin cells to date. The DJ ELO cells had fill factor (FF) >88%, open circuit voltage (Voc) of 2.32 V, and short circuit current density (Jsc) of 13.9 mA/cm
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. ELO DJ cells grown on reclaimed wafers show comparable performance to DJ cells grown on new substrates.