Nanocomposites and nanomaterials
Phenomenon of photoluminescence in anodic column-like nanocomposite from niobium and aluminum oxides
R. Makarov, A. Hoha, A. Pligovka, A. Poznyak, E. Chubenko
Belarusian State University of Informatics and Radioelectronics, Brovki Str. 6, Minsk 220013, The Republic of Belarus
E‑mail of the corresponding author: pligovka@bsuir.by

Formation and research of anodic column-like nanocomposite (ACN) based on niobium and aluminum oxide is a promising direction in the nanotechnology field, due to semiconducting properties of niobium column-like oxide. This specific ACN is also noted for its chemical and thermal stability, electro-chromatic properties and sensitivity to various gases [1]. However, photoluminescence effect of such nanostructures has not been investigated yet.
In this work a niobium oxide-based ACN was formed, its photoluminescence was researched, and the band gap was calculated.
To form niobium oxide-based ACN, two-layer Al/Nb system was deposited on Si wafer by magnetron sputtering, and then upper Al layer electrochemical anodization in 0.2 M aqueous solution of oxalic acid at a voltage of 53 V in potentiostatic mode was carried out, followed by Nb re-anodization sublayer in 0.5 M aqueous solution of boric acid at a voltage of 400 V. Excitation spectra of photoluminescence for niobium oxide-based ACN was then measured, using laser spectrometric complex SOLAR MS 7504i, digital camera Proscan HS 101H as a detector and xenon lamp as a light source.
From the obtained excitation graph a clear peak at a wavelength of 367 nm is received; band gap estimation – 3.34 eV. Emission spectra peak of 453 nm correlates to photon energy of 2.8 eV, corresponding with previous results for niobium oxide obtained by other methods [2].
In conclusion, niobium oxide-based ACN was successfully prepared via electrochemical anodizing. Investigation taken allowed band gap calculation, and in comparison with previous results suggests potential application in optoelectronics and sensors.

1. Özer N., Chen D‑G., Lampert C. M., Preparation and properties of spin-coated Nb2O5 films by the sol-gel process for electrochromic applications // Thin Solid Films.-1996.-277, N 1-2.-P. 162-168.
2. Mozalev A., Bendova M., Vasquez R.M., Pytlicek Z., Llobet E., Hubalek J. Formation and gas-sensing properties of a porous-alumina-assisted 3‑D niobium-oxide nanoﬁlm // Sensors and Actuators B: Chemical.-2016.-229,-P. 587-598.