Experimental Results From Performance Improvement and Radiation Hardening of Inverted Metamorphic Multijunction Solar Cells

This paper discusses results from continued development of inverted metamorphic multijunction (IMM) solar cells with air mass zero (AM0) conversion efficiencies greater than 34%. An experimental best four-junction IMM (IMM4J) design is presented. In an effort to improve IMM performance in space radiation environments, 1-MeV electron irradiation studies are conducted on the individual IMM4J subcells. These data are used to engineer an IMM4J structure with beginning of life AM0 conversion efficiency of approximately 34% and an end of life (EOL) remaining factor greater than 82%, where EOL is defined as performance after exposure to 1-MeV electron irradiation at 1E15 e/cm<formula formulatype="inline"><tex Notation="TeX">$^2$</tex></formula> fluence. Next-generation IMM designs are explored and an avenue toward AM0 conversion efficiencies of greater than 35% is presented.

[1]  C. J. Keavney,et al.  Emitter structures in MOCVD InP solar cells , 1990, IEEE Conference on Photovoltaic Specialists.

[2]  Daniel J. Aiken,et al.  High-efficiency quadruple junction solar cells using OMVPE with inverted metamorphic device structures , 2010 .

[3]  A. Cornfeld,et al.  Development of a four sub-cell inverted metamorphic multi-junction (IMM) highly efficient AM0 solar cell , 2010, 2010 35th IEEE Photovoltaic Specialists Conference.

[4]  M. Yamaguchi.  Radiation resistance of compound semiconductor solar cells , 1995 .

[5]  Martin A. Green,et al.  Solar cell efficiency tables (version 39) , 2012 .

[6]  Hiroshi Kurita,et al.  High efficiency InGaP solar cells for InGaP/GaAs tandem cell application , 1994, Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC).

[7]  M. Al‐Jassim,et al.  High efficiency 1.0 eV GaInAs bottom solar cell for 3-junction monolithic stack , 1990, IEEE Conference on Photovoltaic Specialists.

[8]  A. Cornfeld,et al.  Evolution of the high efficiency triple junction solar cell for space power , 2008, 2008 33rd IEEE Photovoltaic Specialists Conference.

[9]  V. S. Sundaram,et al.  Over 35% efficient GaAs/GaSb stacked concentrator cell assemblies for terrestrial applications , 1990, IEEE Conference on Photovoltaic Specialists.

[10]  R. L. Chapman,et al.  A new high-efficiency GaAs solar cell structure using a heterostructure back-surface field , 1984 .