2-J GaAs Solar Cells on Epi-Ready Flexible Metal Substrates

High-quality epitaxial and single-crystalline-like GaAs thin films grown by metal-organic chemical vapor deposition (MOCVD) on ion-beam textured buffers on flexible metal substrates have been reported earlier. Here we report optimization of lattice-matched InGaP on GaAs for the growth of 2J solar cells. The grown InGaP films were investigated by high-resolution X-ray diffraction (HRXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Further, the flexible InGaP films were used to grow double-junction GaAs solar cells. The 1J GaAs solar cells resulted in 11 % efficiency as reported earlier, show promise for low-cost, flexible, lightweight and high-performance III-V multijunction solar cells which can be a potentially game-changing technology in the photovoltaic market.