GaInP solar cells grown on Ge-on-Ge engineered substrates

Abstract

The Umicore Ge-on-Ge engineered substrate concept consists of a thin epi-ready germanium foil that is weakly attached to a bulk germanium mother substrate. The weak layer is made through modification of the front side of the bulk substrate and allows for easy detachment at any point in the solar cell manufacturing flow. The mother substrate is intended to be re-used multiple times. This paper will present the growth and characterization of III-V layers on Ge-on-Ge engineered substrates as well as the subsequent GaInP single junction device fabrication and characterization. The V-oc of the solar cells was unaffected, which proved the similar performance of bulk Ge and engineered Ge-on-Ge as epi-templates.