Computer modeling results on all-Si cascade solar cells

The properties of a cascade solar cell made entirely of silicon are investigated numerically with the goal of developing an optimal silicon solar cell grown by molecular-beam epitaxy. The cascade cell is modeled as two standard back-surface field cells with abrupt junctions connected by a tunnel junction. A cascade cell would have approximately twice the open-circuit voltage of a single cell. If the minority carriers generated in the front cell can be reflected before reaching the tunnel junction, then the cascade cell will show an increase in efficiency over a single cell by a percentage point.