Silicon Nanowire Design for Ultrahigh Extinction by Dipole Near-Field Interaction in Transparent Solar Cells

Silicon nanowire (SiNW) array transparent solar cells (TSCs) have the advantages of flexibility and visible transparency for a wider application of transparent photovoltaics. The photoelectric performance of SiNW array TSCs is mainly determined by the single SiNW. In this work, a single SiNW is designed to obtain ultrahigh extinction for improving the light absorption and the power conversion efficiency of SiNW array TSCs. According to the analysis of the dipole near-field interaction, the extinction of a single SiNW is strongly related to the relationship between the polarization direction of the incident light and the SiNW scale. When the incident light is linearly polarized, increasing the scale in the polarization direction enhances the extinction, and increasing the scale in the vertical direction of polarization reduces the extinction. Furthermore, optimizing the symmetry of the SiNW achieves a good extinction of natural light and obtains a SiNW with a trilobal top view to improve the extinction of the single SiNW by 85%. Compared with cylindrical SiNW array TSCs, the light absorption increased by 23%, and the power conversion efficiency increased by 14.7%.