Solar cell fabricated on welded thin flexible silicon

Abstract

We present a thin-film crystalline silicon solar cell with an AM1.5 efficiency of 11.5% fabricated on welded 50 μm thin silicon foils. The aperture area of the cell is 1.00 cm2. The cell has an open-circuit voltage of 570 mV, a short-circuit current density of 29.9 mA cm-2 and a fill factor of 67.6%. These are the first results ever presented for solar cells on welded silicon foils. The foils were welded together in order to create the first thin flexible monocrystalline band substrate. A flexible band substrate offers the possibility to overcome the area restriction of ingot-based monocrystalline silicon wafers and the feasibility of a roll-to-roll manufacturing. In combination with an epitaxial and layer transfer process a decrease in production costs can be achieved.