Large-area, epitaxial lift-off, inverted metamorphic solar cells

Large area (20 cm 2 ) epitaxial lifted-off (ELO) triple junction (TJ) solar cells based on inverted metamorphic (IMM) InGaP/GaAs/InGaAs were fabricated. These TJ IMM ELO solar cells exhibited efficiency >29% at one sun AM0 illumination, which is the highest reported efficiency for IMM ELO thin cells to date. The cells had fill factor >85%, open circuit voltage (V oc ) = 2.93 V, and short circuit current density (J sc ) = 16.3 mA/cm 2 . Studies performed on IMM ELO solar cells after >700 thermal cycles between −175 °C and 80 °C revealed no degradation in cell performance. Batches of up to 48 substrates were subjected to reclaim after the ELO process; no degradation in performance was noted between cells grown on prime and reclaimed substrates.