Development of High Efficiency Epitaxial Silicon Solar Cells

Abstract

The optimum fabrication conditions for npp + and n + npp + types epitaxial silicon solar cells are described. Epitaxial p-base and n-surface npp + and n + -diffused n + npp + solar cell structures were grown on both (111) and (100) oriented single crystalline silicon substrates. All the cells have no A.R. coating. The optimum conditions for high efficiency cells are following; resistivity of the p-epitaxial region is the range of 0.1–0.5 ohm-cm and the thickness of it is about 30µm or below, and the n + npp + structure is the important condition. Maximum efficiency of 10.0% has been obtained for both the npp + cell whose resistivity of the p-epitaxial layer was 0.5 ohm-cm and the n + npp + cell with 3 ohm-cm.