Features of the frequency dependence of capacitance–voltage characteristics of a semiconductor structure of a photoelectric converter based on a $p$–$n$ junction with an antireflective film of porous silicon

The frequency dependence of capacitance–voltage characteristics of a semiconductor structure with an antireflective film of porous silicon, which was formed by electrochemical etching above a $p$–$n$ junction, is studied. Photoluminescence spectra of layers of porous silicon of the experimental samples are also examined. It is demonstrated that the capacitance–voltage curves are shaped by competing influences of capacitances of the $p$–$n$ junction and the surface structure forming in a porous Si film due to its inhomogeneity. A structural model of layers of the studied semiconductor structure and a capacitance equivalent circuit are proposed.