Optical Properties of Crystalline Silicon in the Infrared

Silicon has been one of the most well-understood semiconductor materials in the literature. In spite of its mature know-how and technology, there is an absence of reliable values of its wavelength-dependent optical constants, i.e., refractive index and extinction coefficient of monocrystalline silicon in the wavelength range of 1–10 μm, in the literature. These values are critical to fully simulate, model, and understand the optical properties of silicon in the infrared range of wavelengths, as well as to be able to design devices of interest, particularly in the infrared. In this study, the Forouhi–Bloomer dispersion equations have been utilized to predict the functions of the refractive index and extinction coefficient for the entire wavelength spectrum, including the sought 1–10 µm range. The calculated reflectivity and transmissivity are then analyzed and compared to prior findings in the literature.