Optimization of p+ seeding layer for thin film silicon solar cell by liquid phase epitaxy

Abstract

Thickness optimization of heavily doped p-type seeding layer was studied to improve performance of thin film silicon solar cell. We used liquid phase epitaxy (LPE) to grow active layer of 25 mm thickness on p+ seeding layer. The cells with p+ seeding layer of 10 mm to 50 mm thickness were fabricated. The highest efficiency of a cell is 12.95 %, with VOC = 633 mV, JSC = 26.5 mA/cm2, FF = 77.15 %. The p+ seeding layer of the cell is 20 mm thick. As thicker seeding layer than 20 mm, the performance of the cell was degraded. The results demonstrate that the part of the recombination current is due to the heavily doped seeding layer. Thickness of heavily doped p-type seeding layer was optimized to 20 mm. The performance of solar cell is expected to improve with the incorporation of light trapping as texturing and AR coating.