New publication from the SUNLAB: Crystal Growth & Design

A collaboration between between the University of Ottawa SUNLAB and the National Renewable Energy Laboratory in the United States resulted in a recent publication first-authored by PhD candidate Gavin Forcade, in Crystal Growth & Design. In this manuscript, the authors demonstrate the potential of epitaxial growth for facilitating the reuse of substrates.

The journal paper titled “Planarizing spalled GaAs(100) surfaces by MOVPE growth” discusses a method to smooth out rough surfaces left by controlled spalling, a technique used to reuse expensive substrates in III-V photovoltaics. We used Metal-Organic Vapor Phase Epitaxy (MOVPE) to grow a layer of carbon-doped gallium arsenide (C:GaAs) on these rough surfaces. This method successfully filled in the rough areas, using up to 95% of the material to do so. We improved the surface smoothing performance by optimizing the initial substrate surface orientation and growth conditions. This technique can significantly reduce the cost of producing high-efficiency solar cells by allowing the reuse of substrates, and the findings provide guidelines for improving the planarization of other semiconductor surfaces.

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G. P. Forcade, M. W. E. McMahon, N. Yoo, A. N. Neumann, M. Young, J. Goldsmith, S. Collins, K. Hinzer, C. E. Packard and M. A. Steiner, Planarizing spalled GaAs(100) surfaces by MOVPE growth, Crystal Growth & Design, 1528 - 7483 (2024). DOI: 10.1021/acs.cgd.4c01152