MOVPE grown Ga sub(1-x)In sub(x)As solar cells for GaInP/GaInAs tandem applications

Lattice-mismatched Ga sub(1-x)In sub(x)As solar cells with an absorption edge between 900 and 1150 nm have been grown on GaAs substrates. Different graded Ga sub(1-x)In sub(x)As buffer layers and solar cell structures were evaluated to achieve a good electrical performance of the device. External quantum efficiencies comparable to our best GaAs solar cells were measured. The best 1 cm super(2) cell with a bandgap energy of 1.18 eV has an efficiency of 22.6% at AM1.5 g and a short circuit current density of 36.4 mA/cm super(2). To our knowledge, this is the highest reported efficiency for a Ga sub(0.83)In sub(0.17)As solar cell.