https://doi.org/10.15407/jopt.2018.53.169

Optoelectron. Semicond. Tech. 53, 169-180 (2018)

K.V. Michailovska, В.А. Dan’ko, O. Y. Gudymenko, V. P. Klad’ko, I.Z. Indutnyi, P.E. Shepeliavyi, M.V. Sopinskyy

PHOTOLUMINESCENCE PROPERTIES OF SILICON NANOPARTICLES IN MULTILAYERED (SiOx-SiOy)n STRUCTURES WITH POROUS INSULATING LAYERS

The investigations of spectral characteristics and kinetics of photoluminescence (PL) of light-emitting multilayer (nc-Si-SiOx-SiOy)n structures formed on c-Si plates by thermal deposition in vacuum of 30-40 pairs of solid SiOx nanolayers and intermediate porous SiOy nanolayers (x<y≤2) as well as subsequent high-temperature annealing and passivation in HF vapor have been performed. It has been found that the position of the maximum and intensity of PL in these superlattices depends on two factors: the thickness of operating layers and time of passivation in vapor of fluorine-hydrogen acid. This makes it possible to control the spectral composition and intensity of radiation by changing both the thickness of the initial layers in these superlattices and time of passivation. The latter is achieved by using in the structure of the superlattice SiOy porous films as separating layers, through which diffusion of HF vapor into active SiOx layers (where after high-temperature annealing silicon nanoparticles are formed) is possible. The study of PL decay in multilayered (nc-Si–SiOx–SiOy)n samples was performed, and it was ascertained that the decay curves deviate from a single exponential function. The dependence of the radiative recombination rate on the energy of the emitting photons was measured. The average PL lifetime and its dispersion factor in the superlattices with different thicknesses of the bilayers have been obtained. The dependence of these parameters on the time of fluorine-hydrogen processing the samples has been found. Using ellipsometric researches, it has been also found that multilayer (nc-Si-SiOx-SiOy)n superlattices show the effect of polarization conversion, which is caused by the presence of inclined columns in skew-deposited intermediate porous SiOy nanolayers.

Keywords: silicon nanoparticles, photoluminescence, superlattice.