Precise calculation of the optical constants of self-standing nanoporous silicon layers

Abstract

Abstract The precise knowledge of the values of the optical constants (index of refraction, n, and extinction coefficient, k) for nanostructured porous silicon (nanoPS) is a necessary condition to predict the behavior of any optical and photonic devices based on this material. With this objective in mind, a simulation computational program based on the matrix method was used to determine the values of the optical constants in the visible range of self-standing nanoPS films from their experimental reflectance and transmittance spectra. Furthermore, the spectral absorption coefficient (α) was determined from the spectral k values, which motivated to the determination of the values and type of bandgap (direct or indirect) for different porosities