Effects during the cathode polarization of porous silicon
V. Yakovtseva,
S. Volchek,
V. Bondarenko,
M.I. Sayyed,
Taha A. Hanafy,
S. Trukhanov,
A. Bondaruk,
A. Rotkovich,
M.V. Silibin,
T. Zubar,
D. Tishkevich,
A. Trukhanov
Affiliations
V. Yakovtseva
Belarusian State University of Informatics and Radioelectronics, P. Brovka 6, Minsk 220027, Belarus
S. Volchek
Belarusian State University of Informatics and Radioelectronics, P. Brovka 6, Minsk 220027, Belarus
V. Bondarenko
Belarusian State University of Informatics and Radioelectronics, P. Brovka 6, Minsk 220027, Belarus
M.I. Sayyed
Department of Physics, Faculty of Science, Isra University, 1162 Amman, Jordan; Department of Physics and Technical Sciences, Western Caspian University, Baku, Azerbaijan
Taha A. Hanafy
Department of Physics, Faculty of Science, University of Tabuk, Tabuk, Saudi Arabia
S. Trukhanov
Laboratory of Magnetic Films Physics, Scientific-Practical Materials Research Centre of National Academy of Sciences of Belarus, 220072 Minsk, Belarus
A. Bondaruk
Laboratory of Magnetic Films Physics, Scientific-Practical Materials Research Centre of National Academy of Sciences of Belarus, 220072 Minsk, Belarus
A. Rotkovich
Laboratory of Magnetic Films Physics, Scientific-Practical Materials Research Centre of National Academy of Sciences of Belarus, 220072 Minsk, Belarus
M.V. Silibin
Institute for Advanced Materials and Technologies, National Research University of Electronic Technology “MIET”, 124498 Zelenograd, Moscow, Russia; I.M. Sechenov First Moscow State Medical University, Moscow 119435, Russia
T. Zubar
Laboratory of Magnetic Films Physics, Scientific-Practical Materials Research Centre of National Academy of Sciences of Belarus, 220072 Minsk, Belarus
D. Tishkevich
Laboratory of Magnetic Films Physics, Scientific-Practical Materials Research Centre of National Academy of Sciences of Belarus, 220072 Minsk, Belarus; Corresponding author.
A. Trukhanov
Laboratory of Magnetic Films Physics, Scientific-Practical Materials Research Centre of National Academy of Sciences of Belarus, 220072 Minsk, Belarus
The large inner surface of porous silicon (pSi) not only provides unique opportunities for introducing various foreign materials into the open pores, but is also responsible for a lot of processes during the pSi cathode polarization. PSi surface and contact effects are considered in the article. The space charge layer induced by both the surface states and the double electrical layer in the solution is shown to have a decisive influence on the electrical conductivity of the silicon skeleton in the pSi layer. Depending on the depletion degree of the pSi skeleton, the electrochemical deposition of metals is possible either on the entire pSi surface or pore filling from the bottom. The erbium hydroxide formation in the process of the cathode polarization of pSi in the solution of erbium salt is shown to have a chemical nature and is stimulated by the alkalization of the cathode space. The formation of erbium-containing deposits occurs by the following mechanism. First, hydrogen is electrochemically reduced at the cathode. This causes the ion imbalance and leads to the alkalinization in the space near the cathode. The alkaline medium creates conditions for the chemical process of the erbium hydroxide formation. Formed as a gel, erbium hydroxide is physically adsorbed on the cathode surface as a film. The components of the solution are necessarily included in the deposit composition. The accompanying oxidation and dehydrogenation effects during the cathode pSi polarization are considered. Moreover, during the pSi oxidation, the solid phase extends in the pore increases the steric factor, which is essential for the formation of internal oxygen bonds. These effects are characteristic features of any pSi cathode treatment. These formation rules are true for any lanthanide. The obtained results open wide prospects for practical application of Er-filled pSi as a promising material for practical biomedical application as prospective electrodes.
