Portal de Periódicos da CAPES

GaAs 0.75 P 0.25 /Si Dual-Junction Solar Cells Grown by MBE and MOCVD

2015; Institute of Electrical and Electronics Engineers; Volume: 6; Issue: 1 Linguagem: Inglês

10.1109/jphotov.2015.2493365

2156-3381

Tyler J. Grassman, Daniel J. Chmielewski, Santino D. Carnevale, John A. Carlin, Steven A. Ringel,

Semiconductor Quantum Structures and Devices

Monolithic, epitaxial, series-connected GaAs 0.75 P 0.25 /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 GaAs 0.75 P 0.25 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.