Gaas Solar Cells Grown On Sapphire With Multi-Layer Transfer Printed Virtual Substrates

Transfer printed virtual substrates (TPVS) is a promising technique for drastic III-V substrate cost reduction. In this work, we grew a three-period stack of GaAs virtual substrates on a source wafer and transfer printed material from each individual period to a single handle sapphire sub-strate. We characterized metal organic chemical vapor deposition (MOCVD) GaAs solar cell regrowth performance on the printed virtual substrate. Device performance is consistent between the virtual substrate layers, however, the devices presently lag behind performance of identical solar cell structures on conventional substrates. This serves as a first report for numerous critical aspects of the TPVS concept: multi-layer source stacks, MOCVD regrowth, and device results on sapphire handle wafers.