Abstract
We demonstrate the growth of GaAs solar cells by hydride vapor phase epitaxy (HVPE) on epi-ready and previously spalled (110) GaAs wafers as an advance towards a potentially low-cost (110)-based device platform. Controlled spalling offers a fracture-based path to substrate cost amortization, enabling device exfoliation and substrate reuse, but the faceted surface generated during the spalling of (100)-oriented GaAs presents hurdles to direct regrowth of subsequent devices. Spalling of (110) substrates instead eliminates faceting by aligning the substrate surface with the predominant crystal cleavage plane. III-V epitaxy of solar cells is significantly less developed on (110)-oriented substrates, however. Here, we develop (110)-based GaAs solar cells grown by HVPE on epi-ready substrates, demonstrating equal performance to devices grown on the more standard (100) orientation. We also characterize the surface of spalled, (110)-oriented substrates, revealing flat terraces separated by steps with sub-micron-scale height on average. Finally, we present an initial device grown on a previously spalled surface without additional surface re-preparation with nearly 16% efficiency under a simulated AM1.5G spectrum. Together, these results provide preliminary evidence of a potentially low-cost path to enable terrestrial III-V photovoltaics via the (110) substrate orientation.
Original language | American English |
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Pages (from-to) | 962-967 |
Number of pages | 6 |
Journal | IEEE Journal of Photovoltaics |
Volume | 12 |
Issue number | 4 |
DOIs | |
State | Published - 2022 |
Bibliographical note
Publisher Copyright:© 2022 IEEE.
NREL Publication Number
- NREL/JA-5900-81725
Keywords
- GaAs
- HVPE
- hydride vapor phase epitaxy
- III-V
- photovoltaic
- PV
- spalling