Kopin, a provider of heterojunction bipolar transistor (HBT) wafers for cellular phones and wireless local area networks, has been selected for the award of a $600,000 solar cell development contract from NASA. The contract is the second phase of a Small Business Technology Transfer (STTR) program to develop indium nitride (InN)-based quantum dot solar cell technology. Kopin’s partners on this NASA STTR project include groups at Virginia Tech and Magnolia Optical Technologies.
“The goal of this STTR program is to develop high-efficiency solar cells that are resistant to extreme conditions while achieving high solar electric power conversion efficiency,” said Dr. Roger Welser, Kopin’s director of technology and new product development. “The advanced patent-pending solar cell structure incorporating InN-based nanostructures can harness a very large fraction of the solar spectrum while minimizing the effects of high temperatures and high-energy radiation. This technology will enable photovoltaic power systems of future NASA space exploration missions to operate in extreme environments with high temperature and radiation exposures.”
Quantum-dot nanostructures allow the spectral response and operating voltage of a solar cell to be tailored in ways that are not possible with bulk semiconductor materials. In particular, the wide range of energies accessible to InN-based materials provides unique flexibility in designing quantum-dot solar cell structures.
Phase I work demonstrated device-quality InN-based quantum dots exhibiting strong room-temperature photoluminescence, with peak emission energies ranging from the infrared to the ultraviolet. During the Phase II program, the InN-based quantum dots will be embedded within a higher band-gap GaN barrier material to demonstrate high efficiency and immunity to extreme environments.