Luminescent Properties of Nanocomposites Based on Porous Silicon, Nickel, and Nickel Oxide in the Photon Energy Range of 1.4 - 2.9 eV

• Main Authors: Galkin, Nikolay G., Yan, Dmitrii T., Galkin, Konstantin N., Nepomnyaschiy, Aleksandr V., Goroshko, Dmitrii L.
• Format: Conference Proceeding
• Language: English
• Subjects: Annealing; Ions; Mesoporous Silicon; Nanocrystals; Ni deposition; Ni sub oxide; Nickel; Photoluminescence; Radiative recombination; Spectroscopy; Surface morphology; Thermal Annealing
• ISSN: 2771-697X
• DOI: 10.1109/EExPolytech56308.2022.9950797

This paper presents the results of studying the effect of time (5, 6, 7, and 8 minutes) of nickel electrodeposition (Ni ED) at room temperature and annealing at 450°C in an argon atmosphere on the structure, composition, and photoluminescent (PL) properties of mesoporous silicon (meso-PS) and its nanocomposite with Ni (meso-PS/Ni). The SEM and EDX spectroscopy data showed the predominant concentration of Ni on the surface and an insignificant concentration in the near-surface region of the meso-PS. According to Raman and PL spectroscopy data, it was established that after Ni ED in a NiCl 2 solution, nickel sub oxide (NiO x ) with a band gap of up to 2.8 e V is formed in the meso-PS surface layer, which, after short-term annealing (5 and 6 min), is transformed into nickel monoxide nanocrystals (NiO), which leads to a strong (0.2 - 0.9 eV) "blue" shift of the PL maximum (2.4-2.6 eV) of the nanocomposite with meso-PS/Ni with a multiple increase in the PL amplitude. With an increase in the time of Ni ED and storage in air, NiO x , is not formed, and the detected significant (2-18 times) increase in the PL amplitude with a small "red" shift of 0.05-0.1 eV is presumably associated with the formation of radiative recombination centers in the form of ions Ni in the meso-PS matrix. Annealing in argon in this case leads to a decrease in the PL intensity without shifting the PL maxima.