The Polyhedral Specular Reflector: A Spectrum-Splitting Multijunction Design to Achieve Ultrahigh (>50%) Solar Module Efficiencies
Abstract
The most feasible pathway to record 50% efficiency photovoltaic devices is by utilizing many ( >4) junctions to minimize thermalization and nonabsorption losses. Here we propose a spectrum-splitting design, the polyhedral specular reflector (PSR), that employs an optical architecture to divide and concentrate incident sunlight, allowing the incorporation of more junctions compared with traditional monolithic architectures. This paper describes the PSR design and indicates the requirements to achieve a 50% efficiency module by coupling robust cell, optical, and electrical simulations. We predict that a module comprised of the seven subcells with an average external radiative efficiency of at least 3%, an optical architecture capable of a splitting efficiency of at least 88% and 300× concentration, small ( ≤ 1 μm) metallic fingers for subcell contact, and a state-of-the-art power conditioning system ( >98% efficiency) can achieve a module efficiency of 50%, a record for both multijunction cells and modules. We also discuss the flexibility of the design and explore how adjusting the size and type of concentrators can still yield record module efficiencies ( >40%).
Additional Information
© 2018 IEEE. Manuscript received May 23, 2018; revised August 17, 2018; accepted September 19, 2018. Date of publication October 8, 2018; date of current version December 21, 2018. This work was supported in part by the Department of Energy "Light-Material Interactions in Energy Conversion" Energy Frontier Research Center under grant DE-SC0001293, in part by the Dow Chemical Company through the Full Spectrum Project, and in part by the Advanced Research Projects Agency-Energy, U.S. Department of Energy, under Award Number DE-AR0000333. The authors would like to thank Dr. R. Pala for his guidance in setting up the optical characterization. Optical design was supported by a partnership between the DOE "Light-Material Interactions in Energy Conversion" Energy Frontier Research Center under Grant DE-SC0001293 and the Dow Chemical Company through the Full Spectrum Project. Bandgap selection and electrical design was supported by the Advanced Research Projects Agency-Energy, U.S. Department of Energy, under Award Number DE-AR0000333. C.N.E. was supported by the Department of Defense through the National Defense Science & Engineering Graduate Fellowship Program. C.A.F. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE1144469.Additional details
- Eprint ID
- 90254
- DOI
- 10.1109/JPHOTOV.2018.2872109
- Resolver ID
- CaltechAUTHORS:20181011-134846480
- Department of Energy (DOE)
- DE-SC0001293
- Dow Chemical Company
- Department of Energy (DOE)
- DE-AR0000333
- National Defense Science and Engineering Graduate (NDSEG) Fellowship
- NSF Graduate Research Fellowship
- DGE-1144469
- Created
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2018-10-12Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field