Enhanced open circuit voltage in inverted thin film solar cells lattice-matched to InP

摘要

We fabricated InGaAsP (1.05 eV) and InGaAs (0.74 eV) inverted thin film solar cells lattice-matched to InP by molecular beam epitaxy. Thin-film solar cells with a highly reflective mirror on the backside, which can lower the reverse saturation current density of the dark current, were processed on Si supporting substrates. Larger open circuit voltages of 0.587 V for the InGaAsP and 0.335 V for the InGaAs inverted cells were observed, in comparison with those of 0.568 V for the InGaAsP and 0.304 V for the InGaAs upright cells processed on InP substrates. As a result, high efficiencies of 11.76% and 9.58% were achieved in the InGaAsP and InGaAs inverted thin-film cells, respectively.