NASA SBIR 2011 Solicitation


PROPOSAL NUMBER: 11-1 X8.04-9001
SUBTOPIC TITLE: Advanced Photovoltaic Systems
PROPOSAL TITLE: High-Volume Production of Lightweight, Multi-Junction Solar Cells Using 6-inch GaAs

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
MicroLink Devices
6457 Howard Street
Niles, IL 60714 - 3301
(847) 588-3001

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Christopher Youtsey
6457 West Howard Street
Niles, IL 60714 - 3301
(847) 588-3001 Extension :16

Estimated Technology Readiness Level (TRL) at beginning and end of contract:
Begin: 3
End: 4

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
Very large solar arrays to power future solar electric propulsion systems will require a new generation of solar cells that are not only high efficiency, but also light weight and significantly lower cost than existing multijunction solar cells based on Ge substrates. The large volume of solar cells required for individual missions (hundreds of kilowatts to megawatts) also presents significant manufacturing challenges. MicroLink Devices' multijunction solar cells based on epitaxial lift off (ELO) provide the unique combination of high efficiency, high specific power, and low cost by enabling reuse of the GaAs substrate after lift off. The use of GaAs substrates leverages a platform well-established by the GaAs IC industry at 6-inch diameter, which is also a significant enabler for cost reduction and volume production. Larger substrates not only reduce epitaxial growth and fabrication costs, but improve wafer utilization when fabricating large-area solar cells. MicroLink Devices' ELO solar cells are also highly flexible, which enables new approaches for panel fabrication and deployment.

In this SBIR program we will demonstrate the capability for high-volume epitaxial lift off using 6-inch GaAs material. Our previous development efforts at MicroLink Devices have focused primarily on 4-inch wafers. We will fabricate the first large-area (20 cm2) multijunction ELO solar cells on 6-inch GaAs and compare performance with 4-inch ELO material. To support the fabrication of hundreds of kilowatts of solar cells for very large arrays, it is essential that the ELO substrate removal process is capable of supporting very high volumes of wafers on the scale of hundreds to thousands of wafers per day. We will demonstrate a 6-inch ELO process based on well-established semiconductor industry volume production tool sets and batch processing to achieve high throughput. The impact of using large wafer batches on the ELO process yield and device performance will be quantified.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
MicroLink Devices' multi-junction ELO solar cells are well-suited for future very large solar arrays to support solar electric propulsion (SEP) missions. Conventional solar-powered satellites can also benefit from lower-cost alternatives to existing Ge-based multi-junction solar cells. The cells are useable in solar-powered unmanned aerial vehicles (UAVs).

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
MicroLink Devices' multi-junction ELO solar cells are a potential replacement for conventional solar cells for military and civilian applications. The combination of high efficiency and low weight also make the cells ideal for powering unmanned aerial vehicles (UAVs). There are also emerging military and commercial applications for high-efficiency, flexible solar sheets for terrestrial power generation.

TECHNOLOGY TAXONOMY MAPPING (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.)
Manufacturing Methods
Materials & Structures (including Optoelectronics)
Materials (Insulator, Semiconductor, Substrate)
Processing Methods
Sources (Renewable, Nonrenewable)

Form Generated on 11-22-11 13:43