Open AccessGaAs0.75P0.25/Si Dual-Junction Solar Cells Grown by MBE and MOCVD
Author(s) -
Tyler J. Grassman,
Daniel J. Chmielewski,
Santino D. Carnevale,
John A. Carlin,
Steven A. Ringel
Publication year - 2015
Publication title -
ieee journal of photovoltaics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.023
H-Index - 72
eISSN - 2156-3403
pISSN - 2156-3381
DOI - 10.1109/jphotov.2015.2493365
Subject(s) - photonics and electrooptics
Monolithic, epitaxial, series-connected GaAs0.75P0.25/Si dual-junction solar cells, grown via both molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), are reported for the first time. Fabricated test devices for both cases show working tandem behavior, with clear voltage addition and spectral partitioning. However, due to thermal budget limitations in the MBE growth needed to prevent tunnel junction failure, the MBE-grown GaAs0.75P0.25 top cell was found to be lower quality than the equivalent MOCVD-grown device. Additionally, despite the reduced thermal budget, the MBE-grown tunnel junction exhibited degraded behavior, further reducing the overall performance of the MBE/MOCVD combination cell. The all-MOCVD-grown structure displayed no such issues and yielded significantly higher overall performance. These initial prototype cells show promising performance and indicate several important pathways for further device refinement.