Heterojunction Bipolar Transistors? Huh? Kopin + NASA Have A Solar Clue…

Kopin Corp. provides heterojunction bipolar transistor (HBT) wafers for cellular phones and wireless local area networks and the company has just received an award of a $600,000 for 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. 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 demo’d 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. Dr. John C.C. Fan, Kopin President and Chief Executive Officer, stated, “This STTR project is part of Kopin’s long-term goal to address the emerging terrestrial renewable energy market by realizing the ultimate objective of high conversion efficiency at low costs. Kopin is currently exploring a number of options for synthesizing high-performance photovoltaic materials. Ultimately our approaches can provide pathways for realizing solar cells with power conversion efficiency approaching 60 percent, well beyond the current state-of-the-art efficiency of 40 percent.”—Taunton, Massachusetts