Improved performance thin solar cells

A silicon solar cell device structure was developed to improve performance from thin cells. The design has collecting junctions both on the illuminated and most of the dark sides. Since the two junctions function interdependently, the device is called a tandem junction cell (TJC). The photoresponse performance of cells was measured in two modes, with either collection from the junctions on both sides, or collection from only the nonilluminated side. Efficient current collection from TJC cells was observed in both modes, and current collection improved as the cell thickness was reduced. At the calculated optimum thickness of 30-50 µm, collection for the two modes should be equivalent.