Manufacturing of High-Efficiency Bi-Facial Tandem Concentrator Solar Cells: February 20, 2009--August 20, 2010
Spire Semiconductor made concentrator photovoltaic (CPV) cells using a new bi-facial growth process and met both main program goals: a) 42.5% efficiency 500X (AM1.5D, 25C, 100mW/cm2); and b) Ready to supply at least 3MW/year of such cells at end of program. We explored a unique simple fabrication process to make a N/P 3-junction InGaP/GaAs/InGaAs tandem cells . First, the InGaAs bottom cell isgrown on the back of a GaAs wafer. The wafers are then loaded into a cassette, spin-rinsed to remove particles, dipped in dilute NH4OH and spin-dried. The wafers are then removed from the cassette loaded the reactor for GaAs middle and InGaP top cell growth on the opposite wafer face (bi-facial growth). By making the epitaxial growth process a bit more complex, we are able to avoid more complexprocessing (such as large area wafer bonding or epitaxial liftoff) used in the inverted metamorphic (IMM) approach to make similar tandem stacks. We believe the yield is improved compared to an IMM process. After bi-facial epigrowth, standard III-V cell steps (back metal, photolithography for front grid, cap etch, AR coat, dice) are used in the remainder of the process.
- Research Organization:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1018101
- Report Number(s):
- NREL/SR-5200-51767; NAT-9-88012-04
- Country of Publication:
- United States
- Language:
- English
Similar Records
Lattice-Mismatched GaAs/InGaAs Two-Junction Solar Cells by Direct Wafer Bonding
Over 30{percent} efficient InGaP/GaAs tandem solar cells
Final Report for PV Incubator Subcontract No. NEU-0-99010-09: March 29, 2010 - March 28, 2011
Conference
·
Sat Dec 31 23:00:00 EST 2005
·
OSTI ID:944001
Over 30{percent} efficient InGaP/GaAs tandem solar cells
Journal Article
·
Tue Dec 31 23:00:00 EST 1996
· Applied Physics Letters
·
OSTI ID:463433
Final Report for PV Incubator Subcontract No. NEU-0-99010-09: March 29, 2010 - March 28, 2011
Technical Report
·
Sat Mar 31 20:00:00 EDT 2012
·
OSTI ID:1039807