Metamorphic Epitaxy for Multijunction Solar Cells

Journal Article · Tue Mar 01 04:00:00 EST 2016 · MRS Bulletin

DOI:https://doi.org/10.1557/mrs.2016.25· OSTI ID:1245126

France, Ryan M.; Dimroth, Frank; Grassman, Tyler J.; King, Richard R.

Multijunction solar cells have proven to be capable of extremely high efficiencies by combining multiple semiconductor materials with bandgaps tuned to the solar spectrum. Reaching the optimum set of semiconductors often requires combining high-quality materials with different lattice constants into a single device, a challenge particularly suited for metamorphic epitaxy. In this article, we describe different approaches to metamorphic multijunction solar cells, including traditional upright metamorphic, state-of-the-art inverted metamorphic, and forward-looking multijunction designs on silicon. We also describe the underlying materials science of graded buffers that enables metamorphic subcells with low dislocation densities. Following nearly two decades of research, recent efforts have demonstrated high-quality lattice-mismatched multijunction solar cells with very little performance loss related to the mismatch, enabling solar-to-electric conversion efficiencies over 45%.

• Research Organization: NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1245126
• Report Number(s): NREL/JA-5J00-65434
• Journal Information: MRS Bulletin, Journal Name: MRS Bulletin Journal Issue: 3 Vol. 41; ISSN 0883-7694
• Publisher: Materials Research Society
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
dislocations
epitaxy
photovoltaic