NASA SBIR 2007 Solicitation


PROPOSAL NUMBER: 07-2 S3.03-9444
SUBTOPIC TITLE: Power Generation and Storage
PROPOSAL TITLE: Nanostructured InGaP Solar Cells

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Kopin Corporation
200 John Hancock Road
Taunton, MA 02780 - 7320
(508) 824-6696

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Roger Welser
200 John Hancock Road
Taunton, MA 02780 - 7320
(508) 824-6696

Expected Technology Readiness Level (TRL) upon completion of contract: 3 to 4

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
Current matching constraints can severely limit the design and overall performance of conventional serially-connected multijunction solar cells. The goal of this SBIR program is to enhance the operating tolerance of high efficiency III-V solar cells by employing nanostructured materials in advanced device designs. A larger fraction of the solar spectrum can potentially be harnessed while maximizing the solar cell operating voltage by embedding thin layers of narrow band gap material in a higher band gap matrix. Nanostructured devices thus provide a means to decouple the usual dependence of short circuit current on open circuit voltage that limits conventional solar cell design. While previous experimental work on quantum well or quantum dot solar cell devices has typically employed GaAs as the wide band gap matrix, we take a different approach, instead employing InGaP as the barrier material. During the Phase I effort, we observed that thin InGaP layers can be extremely effective at reducing the dark current. A novel device structure resulted in over a 100 mV enhancement in the open circuit voltage of GaAs PIN diodes solar cells without any degradation in the short circuit current. The Phase II program will aim to further optimize single-junction nanostructured InGaP solar cells and then utilize these cells as building blocks to construct robust, multijunction photovoltaic devices with power conversion efficiencies approaching 40%. Ultimately, the technical approach employed in this program has the potential of achieving conversion efficiencies exceeding 50% with a single p-n junction device, enabling improved overall performance and lower manufacturing costs.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Future space exploration missions will require photovoltaic power systems capable of operating over a wide range of conditions, ranging from extreme environments with high temperatures and tremendous radiation exposures to low temperature, low intensity conditions. Conventional multijunction solar cells can provide high conversion efficiencies, but only under limited environmental conditions. The near term objective of this SBIR program is to build a solar cell using nanostructured wide band gap materials that matches the conversion efficiency of conventional multijunction technologies while performing over a much wider range of operating conditions. The technology developed during this program is expected to have immediate market opportunities as power systems for NASA science missions.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The SBIR project described here is part of a larger effort to realize the ultimate objective of third generation photovoltaics, namely ultra-high conversion efficiency at low costs. The wider operating conditions enabled by nanostructured InGaP solar cells would substantially enhance the overall performance of terrestrial concentrator photovoltaic systems. This technology could thus accelerate the adoption of photovoltaics into the renewable energy market to address the world's growing energy needs without degrading the environment. In addition to its potential commercial value and social benefits, this SBIR program will enhance the technical understanding of quantum well and quantum dot devices.

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.

Photovoltaic Conversion
Radiation-Hard/Resistant Electronics
Renewable Energy
Semi-Conductors/Solid State Device Materials

Form Generated on 10-23-08 13:36