High Efficiency InAsSb / AlAsSb Quantum Dot Solar Cells

Magnolia Solar proposes to develop an innovative high efficiency single junction solar cell working with Prof. Diana Huffaker and her group and utilizing multi photon absorption in InAsSb/AlAsSb quantum dot solar cells. The proposed structure has unique qualities required by Intermediate band solar cell theory to achieve ultra high conversion efficiency. This system has a potential to achieve efficiencies over 50% under concentrated light conditions. The proposed structure has optimum band alignment as well as bandgap for Quantum dot and barrier materials. InAsSb QDs in AlAsSb barriers forms a type II band alignment which has long carrier life times and hence high carrier extraction efficiencies are possible. During the Phase I STTR effort, we will synthesize InAsSb dots with excellent structural and optical properties and demonstrate the technical feasibility of InAsSb Quantum Dot solar cells. Device simulation and modeling will help supplement the device optimization work. Our broad experience in band engineering, simulation and device design will help obtain optimum material properties needed for demonstrating multi-photon solar cells. BENEFIT: The terrestrial, Defense and Spacecraft power photovoltaic markets provide a significant commercial opportunity for the technology developed during this SBIR effort. The worldwide PV market generates over $4.5 billion (US) per year in revenue and has been growing at over 30% annually since the late 1990s. The emphasis on renewal energy and more of the defense energy needs will grow over the next decade and is expected to grow to over 100 Billion in the next ten years. Continued growth in the commercial PV market is currently being hampered by market down turn, while space-based PV systems will utilize technologies that improve radiation hardness, operating temperature range, efficiency, and specific power. Our technology development and commercialization strategy involves several distinct steps. Magnolia has detailed the tremendous long term benefits of increasing the efficiency of Solar cells for terrestrial applications. In addition use of the micro-concentrators also provides a means of inserting Quantum Dot-based solar cells with innovative nanostructured coatings into the renewable energy market.