Towards a III-V solar cell with a metamorphic graded buffer directly grown on v-groove Si substrates

V-groove Si substrates offer a promising route for the direct growth of III-V solar cells on low-cost, photovoltaic-grade Si. In this work, we develop a method for coalescing GaP nucleated on V-groove substrates into thin films suitable for the growth of III-V solar cells. We demonstrate the ability to suppress nucleation-related defects by modifying the V-groove substrate to cover the (0 0 1)-oriented Si V-groove tops with SiN x . A threading dislocation density (TDD) of 5 × 107 cm−2 was measured with electron channeling contrast imaging. Continuing work will focus on further reducing the TDD and the growth of a GaAs solar cell on a GaP on V-groove Si template.