Copper-indium-gallium selenide is an ideal absorber for photovoltaic devices, and is considered the most promising material system for low-cost thin-film solar cells. It is, however, a complex, heavily defected material used in polycrystalline layers. Although very high efficiency modules have been made from copper-indium-gallium selenide in the laboratory, these efficiencies have been limited in production modules. A better understanding of the relationship between the material and the device properties is needed, and this project will develop an associated-solution defect model for use in understanding this relationship. In Phase I, an existing copper-indium selenide model will be improved and modified into a copper-indium-gallium selenide material model. This model will be tested, run, and used to predict and explain published solar cell material properties. The materials model will be used as the basis for a Phase II device model that will link material growth, material properties, and device properties in copper-indium-gallium selenide solar cells.
Commercial Applications and Other Benefits as described by the awardee: The model should serve as a development tool to enable the low-cost manufacture of high-efficiency modules for the United States and world photovoltaic markets. These modules would in turn expand the photovoltaic markets and help to stabilize United States energy prices
