Dielectric Metasurface Light Trapping Structure for Silicon Thin Film Solar Cells

In commercial silicon solar cells, silicon material accounts for about 40% of the total cost. One efficient way is to decrease the thickness of silicon solar cells. Using light trapping structures on solar cells can reduce the optical loss so as to improve the power conversion efficiency, which is very vital for thin film silicon solar cells. In this paper, we propose a dielectric metasurface light trapping structure for silicon thin film solar cells. The metasurface structure is designed using the FDTD method, and its structure parameters are optimized. Moreover, we fabricate the metasurface light trapping structure on silicon. Its light trapping ability is evaluated in the near-infrared region. The reflectance measurement shows that the dielectric metasurface structure has better anti-reflection performance and angular response than the inverted pyramid structure for $10 \mu {\mathrm {m}}$ thick silicon. Owing to its planar surface, the metasurface structures can be used in the multi-junction solar cells, for example, perovskit/silicon tandem solar cells.