Novel Solar Cell with Dramatically Increased Efficiency


Invention: The University of Florida is seeking companies interested in commercializing a breakthrough in solar cell energy a renewable form of energy harvesting that can be used to generate electricity more efficiently. Electricity production is the number one use of renewable energy in the United States with 51 percent of all renewable energy being used by this sector in 2007 according to the Energy Information Administration. Although the efficiency of organic solar cells has been improving steadily since the initial creation the current forms of solar cell energy still offer an extremely low rate of efficiency with an average of about five percent. Solar cells are performing far below their theoretical efficiency limits and higher efficiency is necessary for such alternative energy sources to be used in commercial settings. Researchers at the University of Florida have developed a novel solar cell that harvests energy from the full spectrum of light dramatically increasing its efficiency. Technology: Inorganic nanocrystals are currently used in hybrid organic-inorganic or all-inorganic solar cells providing power conversion efficiencies in the range of two to three percent. In these devices nanocrystals based on binary compound semiconductors are synthesized and processed in solution. To efficiently absorb light in the entire solar spectrum which spans from ultraviolet to visible to near infrared the energy gap of the light absorber in the solar cells needs to be optimized. At the same time the energy level alignment between different materials in the active region will also have to be optimized in order to minimize the energy loss during charge generation and transport. To greatly enhance efficiency researchers at the University of Florida have developed solar cells in which the band gap the energy difference between the conduction and valence bands and the electron affinity the energy difference between the vacuum level and the conduction band are independently optimized. These solar cells utilize alloyed semiconductor nanocrystals instead of the binary semiconductors leading to enhanced efficiency. For nanocrystals based on ternary semiconductor alloys the solar cell has two independent variables to tune its band gap and electron affinity making it possible to simultaneously achieve the optimized band gap and electron affinity. For nanocrystals based on quarternary semiconductor alloys the additional composition variable will provide even more freedom to optimize the two important material properties. Applications: Design for more efficient solar cells


1) Utilizes low cost materials maximizing profit potential 2) Provides opportunity to create low-cost electricity from solar energy providing a marketable advantage in the rapidly growing field of alternative energy 3) Utilizes alloyed semiconductor nanocrystals which provide maximum efficiency providing a clear competitive advantage 4) Utilizes two independent variables to tune its band gap and electron affinity making it possible to simultaneously achieve the optimized band gap and electron affinity for maximum efficiency

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