Title:	Highly Reliable Low Concentration InGaP/GaAs/Si 3-Junction Solar Cells with Smart Stack Technology
Author(s):	K. Makita, H. Mizuno, R. Oshima, T. Tayagaki, M. Baba, N. Yamada, H. Takato, T. Sugaya
Keywords:	Multijunction Solar Cell, Silicon, III-V Semiconductors, Nanoparticles
Topic:	New Materials and Concepts for Photovoltaic Devices
Subtopic:	New Materials and Concepts for Cells and Modules
Event:	33rd European Photovoltaic Solar Energy Conference and Exhibition
Session:	1AO.3.1
Pages:	27 - 29
ISBN:	3-936338-47-7
Paper DOI:	10.4229/EUPVSEC20172017-1AO.3.1
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Low concentration multi-junction (MJ) solar cells have a practical solution to consist with high efficiency and low cost. We have demonstrated a low concentration InGaP/GaAs/Si 3-junction solar cell with mechanical stacking method. In this development, our key technology is the direct bonding using conductive nanoparticle alignment, which is named “Smart Stack” technology. Using this technology, we fabricated an InGaP/GaAs/Si 3-junction solar cell and observed the maximum efficiency of 23.74% at 8.0 suns (AM1.5g). In addition, we discuss the reliability of InGaP/GaAs/Si 3-junction solar cells showing the results of accelerated aging test and thermal cycling test. It was confirmed that our solar cells have high long-term reliability under sever conditions. Appling general lifetime estimation method with Arrhenius plot, the life time under 10 suns was estimated to be more than 1.5×105 hours at 60. These results strongly suggested the high potential of our Smart Stack technology to achieve low cost and highly reliable mechanically stacked MJ solar cells for practical use.