Title :
Monolithic two-terminal GaAs/Ge tandem space concentrator cells
Author :
Wojtczuk, S. ; Tobin, S. ; Sanfacon, M. ; Haven, V. ; Geoffroy, L. ; Vernon, S.
Author_Institution :
Spire Corp., Bedford, MA, USA
Abstract :
GaAs/Ge two-junction tandems up to 23.4% efficient at 9 AM0 suns were made. This efficiency is a record for a monolithic, two-terminal GaAs/Ge tandem cell, and also exceeds the best efficiency reported (23%) for a single-junction GaAs concentrator at 10 AM0 suns. A GaAs top cell was epitaxially grown on GaAs and Ge wafers simultaneously; the GaAs growth forms a bottom cell in the Ge to make a two-junction tandem cell, while the GaAs top cell on the GaAs substrate is a single-junction experimental control. The best GaAs/Ge tandem was three percentage points more efficient than the best control GaAs/GaAs concentrator; the difference is due to the active Ge bottom cell
Keywords :
III-V semiconductors; elemental semiconductors; gallium arsenide; germanium; semiconductor epitaxial layers; solar cells; solar energy concentrators; 10 AM0 suns; 23.4 percent; 9 AM0 suns; GaAs-Ge; epitaxial growth; monolithic solar cells; tandem space concentrator cells; two-junction tandem cell; two-terminal solar cells; Aerospace simulation; Filters; Gallium arsenide; NASA; Photoconductivity; Substrates; Sun; Testing; Thermal conductivity; Thermal expansion;
Conference_Titel :
Photovoltaic Specialists Conference, 1991., Conference Record of the Twenty Second IEEE
Conference_Location :
Las Vegas, NV
Print_ISBN :
0-87942-636-5
DOI :
10.1109/PVSC.1991.169185
