PreprintArticleVersion 2Preserved in Portico This version is not peer-reviewed
Super-Multi-Junction Solar Cell, Device Configuration with the Potential of More Than 50 % of the Annual Energy Conversion Efficiency (Non-Concentration)
Version 1
: Received: 20 September 2019 / Approved: 21 September 2019 / Online: 21 September 2019 (09:19:47 CEST)
Version 2
: Received: 9 October 2019 / Approved: 14 October 2019 / Online: 14 October 2019 (09:56:10 CEST)
Araki, K.; Ota, Y.; Saiki, H.; Tawa, H.; Nishioka, K.; Yamaguchi, M. Super-Multi-Junction Solar Cells—Device Configuration with the Potential for More Than 50% Annual Energy Conversion Efficiency (Non-Concentration). Appl. Sci.2019, 9, 4598.
Araki, K.; Ota, Y.; Saiki, H.; Tawa, H.; Nishioka, K.; Yamaguchi, M. Super-Multi-Junction Solar Cells—Device Configuration with the Potential for More Than 50% Annual Energy Conversion Efficiency (Non-Concentration). Appl. Sci. 2019, 9, 4598.
Araki, K.; Ota, Y.; Saiki, H.; Tawa, H.; Nishioka, K.; Yamaguchi, M. Super-Multi-Junction Solar Cells—Device Configuration with the Potential for More Than 50% Annual Energy Conversion Efficiency (Non-Concentration). Appl. Sci.2019, 9, 4598.
Araki, K.; Ota, Y.; Saiki, H.; Tawa, H.; Nishioka, K.; Yamaguchi, M. Super-Multi-Junction Solar Cells—Device Configuration with the Potential for More Than 50% Annual Energy Conversion Efficiency (Non-Concentration). Appl. Sci. 2019, 9, 4598.
Abstract
The highest efficiency solar cell won in the efficiency race does not always give the most excellent annual energy yield in the real world solar condition that the spectrum is ever-changing. The study of the radiative coupling of the concentrator solar cells implied that the efficiency could increase by the recycle of the radiative recombination generated by the surplus current in upper junction. Such configuration is called by a super-multi-junction cell. We expanded the model in the concentrator solar cell to non-concentrating installation. It was shown that this super-multi-junction cell configuration was found robust and can keep the maximum potential efficiency (50 % in realistic spectrum fluctuation) up to 10 junctions. The super-multi-junction cell is also robust in the bandgap engineering of each junction. Therefore, the future multi-junction may not be needed to tune the bandgap for matching the standard solar spectrum, as well as relying upon artificial technologies like ELO (Epitaxial lift-off), wafer-bonding, mechanical-stacking, and reverse-growth, but merely uses up-right and lattice-matching growth technologies. We have two challenging techniques; one is the optical cap layer that may be the directional photon coupling layer in the application of the photonics technologies, and another is the high-quality epitaxial growth with almost 100 % of the radiative efficiency.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Commenter: Kenji Araki
Commenter's Conflict of Interests: Author