Characterization of Black Silicon Using Effective Medium Theory and Terahertz Time-Domain Spectroscopy

We present a novel, non-contact method to characterize black Si using terahertz time-domain spectroscopy (THz-TDS) and effective medium theory (EMT). By analyzing transmission spectra, we extract the refractive index (RI) of black Si surfaces and apply EMT to estimate the silicon volume fraction, quantitatively describing its morphology. This approach advances beyond previous THz studies by providing a comprehensive, non-destructive technique for randomly structured black Si, laying the groundwork for future analysis in solar cell applications.