@inproceedings{04aaeb1600794b92a6781e98cf1b7776,
title = "Triple-junction solar cell efficiencies above 32\%: The promise and challenges of their application in high-concentration-ratio PV systems",
abstract = "Results from Spectrolab-grown Ga0.5In0.5P/GaAs/Ge structures optimized for the AM1.5D spectrum are described along with progress toward developing next-generation multijunction solar cells for high concentration ratios (X). The epitaxially-grown layers were processed into triple junction cells both at Spectrolab and NREL, and I-V tested vs. X. Cells were tested with efficiencies as high as 32.4\% near 372 suns. The FF limited the performance with increasing X as a result of the increased role of the series resistance. The Voc vs. X showed its log-linear dependence on Isc over 1000 suns. Based on recent cell improvements for space applications, multijunction cells appear to be ideal candidates for high efficiency, cost effective, PV concentrator systems. Future development of new 1-eV materials for space cells, and further reduction in Ge wafer costs, promises to achieve cells with efficiencies < 40\% that cost \$0.3/W or less at concentration levels between 300 to 500 suns.",
author = "Cotal, \{H. L.\} and Lillington, \{D. R.\} and Ermer, \{J. H.\} and King, \{R. R.\} and Karam, \{N. H.\} and Kurtz, \{S. R.\} and Friedman, \{D. J.\} and Olson, \{J. M.\} and Ward, \{J. S.\} and A. Duda and Emery, \{K. A.\} and T. Moriarty",
note = "Publisher Copyright: {\textcopyright} 2000 IEEE.; 28th IEEE Photovoltaic Specialists Conference, PVSC 2000 ; Conference date: 15-09-2000 Through 22-09-2000",
year = "2000",
doi = "10.1109/PVSC.2000.916044",
language = "English (US)",
series = "Conference Record of the IEEE Photovoltaic Specialists Conference",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
pages = "955--960",
booktitle = "Conference Record of the 28th IEEE Photovoltaic Specialists Conference - 2000",
}