Impurity and defect engineering approaches for realization of 18% commercial silicon solar cells

The Silicon Materials Program, managed by the National Renewable Energy Laboratory (NREL) for the US Department of Energy (DOE), emphasizes basic research issues in solar cell technologies that are critical to achieving 18% efficient commercial silicon solar cells in the near future. This program supports subcontracted research teams in topics of analysis of commercial silicon, clarification of the physics of point defect processes, and application of these processes in new device fabrication techniques. The program also includes in-house projects in crystal growth, investigation of advanced processes, materials characterization, and development of characterization techniques. In this paper, we provide an overview of significant results and indicate planned directions for future research in the program.