Preparation of multilayer periodic CaF2/Si/CaF2/Si (111) structures with photoluminescence in the visible spectrum

The paper presents a method for obtaining some multilayer periodic CaF2/Si/CaF2/Si (111) structures with an emissivity in the visible region of the spectrum. A feature of this technique is that the deposition of Si and CaF2 layers was carried out at room temperature, followed by pulsed an-nealing. The photoluminescence spectra of the grown sample were obtained and measured at excitation wavelengths of 325 nm and 405 nm. The study of low-temperature photoluminescence was carried out with a laser with a wave-length of 405 nm, since no radiation in the structure was observed upon excitation with a laser with a wavelength of 325 nm. The photoluminescence spectra measured at room temperature and liquid nitrogen temperature are presented, according to which the shift of the photoluminescence maximum by 20 nm was established. The FWHM decreased from 284 nm to 210 nm with decreasing tem-perature.