Heterogeneously integrated high-performance GaAs single-junction solar cells on copper

Abstract

We present the heterogeneous integration of GaAs a single-junction solar cell (SC) on copper (Cu) via electroplating and epitaxial lift-off. We characterized the layer quality and the residual strain of the transferred SC layer through X-ray diffraction measurements and Raman spectroscopy. These results indicated that the fabrication process of SCs was quite stable, providing a high-quality film with a relatively small residual compressive strain. The SC transferred on Cu showed a highenergy conversion efficiency of 19.6% at 1sun illumination. In addition, we obtained a peak energy conversion efficiency of 20.8% at 2.5 suns in a solar concentrator.