Designing an Epitaxially-Integrated DBR for Dislocation Mitigation in Monolithic GaAsP/Si Tandem Solar Cells

Journal Article · 31 December 2019 · IEEE Journal of Photovoltaics

DOI: https://doi.org/10.1109/JPHOTOV.2020.3043105 · OSTI ID:1728449

Lepkowski, Daniel L.  ^[1]; Kasher, Tal ^[2]; Grassman, Tyler J.  ^[2]; Ringel, Steven A. ^[2]

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1. The Ohio State Univ., Columbus, OH (United States); The Ohio State University
2. The Ohio State Univ., Columbus, OH (United States)

This work explores epitaxially-integrated distributed Bragg reflectors (DBR) as a strategy to mitigate the impact of threading dislocations on the performance of monolithic GaAs_0.75P_0.25/Si tandem solar cells. The constraints present due to materials availability and the optical transmission profile of the GaAs_0.75P_0.25 top cell require the use of an enhanced bandwidth DBR design achieved by combining two narrow-band DBR’s with different central wavelengths. Here, the impact of this DBR structure on JSC, along with the competing effects of threading dislocation density (TDD), are investigated using a robust, experimentally informed analytical model. Implementing this DBR within the GaAs_0.75P_0.25/Si tandem cell structure is predicted to yield a short circuit current enhancement equivalent to an ~1.8× reduction in TDD, providing a clear demonstration of its promise as a design methodology for mitigating the impact of non-negligible defect populations.

• Research Organization: The Ohio State Univ., Columbus, OH (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: EE0007539
• OSTI ID: 1728449
• Journal Information: IEEE Journal of Photovoltaics, Journal Name: IEEE Journal of Photovoltaics Journal Issue: 2 Vol. 11; ISSN 2156-3381
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English