Terahertz time domain spectroscopy of vertical silicon nanowires

The complex dielectric constants of vertically aligned silicon nanowires (SiNWs) are measured by using terahertz time domain spectroscopy (THz-TDS). The SiNWs are fabricated on a (100) silicon wafer by a metal-assisted chemical etching method. It is demonstrated that the absorption coefficient of the SiNWs is significantly larger than that of a bare silicon wafer at THz band.