Research output: Contribution to journal › Article › peer-review
Nanoscale potential fluctuations in nonstoichiometrics tantalum oxide. / Gritsenko, Vladimir A.; Volodin, Vladimir A.; Perevalov, Timofey V. et al.
In: Nanotechnology, Vol. 29, No. 42, 425202, 15.08.2018.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Nanoscale potential fluctuations in nonstoichiometrics tantalum oxide
AU - Gritsenko, Vladimir A.
AU - Volodin, Vladimir A.
AU - Perevalov, Timofey V.
AU - Kruchinin, Vladimir N.
AU - Gerasimova, Alina K.
AU - Aliev, Vladimir Sh
AU - Prosvirin, Igor P.
PY - 2018/8/15
Y1 - 2018/8/15
N2 - The atomic and electronic structure of nonstoichiometric amorphous tantalum oxide (TaOx) films of different composition has been investigated by means of electron microscopy, x-ray photoelectron spectroscopy, Raman and infrared spectroscopy. The dispersion of the absorption coefficient and refraction index has been studied by spectral ellipsometry. The optical spectra were interpreted using the results of a quantum-chemical simulation for crystalline orthorhombic TaOx. It was found that the presence of oxygen vacancies in the oxygen-deficient TaOx film show an optical absorption peak at 4.6 eV. It has been established that TaOx consists of stoichiometric Ta2O5, metallic Ta clusters less than 20 nm in size, and tantalum suboxides TaOy (y < 2.5). The model of nanoscale potential fluctuations of TaOx bandgap in the range of 0-4.2 eV is proposed and justified. The design of the flash memory element based on the effect of localization of electrons and holes in Ta metallic nanoclusters in the TaOx matrix is proposed.
AB - The atomic and electronic structure of nonstoichiometric amorphous tantalum oxide (TaOx) films of different composition has been investigated by means of electron microscopy, x-ray photoelectron spectroscopy, Raman and infrared spectroscopy. The dispersion of the absorption coefficient and refraction index has been studied by spectral ellipsometry. The optical spectra were interpreted using the results of a quantum-chemical simulation for crystalline orthorhombic TaOx. It was found that the presence of oxygen vacancies in the oxygen-deficient TaOx film show an optical absorption peak at 4.6 eV. It has been established that TaOx consists of stoichiometric Ta2O5, metallic Ta clusters less than 20 nm in size, and tantalum suboxides TaOy (y < 2.5). The model of nanoscale potential fluctuations of TaOx bandgap in the range of 0-4.2 eV is proposed and justified. The design of the flash memory element based on the effect of localization of electrons and holes in Ta metallic nanoclusters in the TaOx matrix is proposed.
KW - density functional theory
KW - ellipsometry
KW - nanoscale potential fluctuations
KW - Raman scattering
KW - ReRAM
KW - tantalum oxide
KW - x-ray photoelectron spectroscopy
KW - HFOX
KW - CHARGE-TRANSPORT
KW - RAMAN-SCATTERING
KW - TAOX
KW - FILMS
KW - SPECTROSCOPY
KW - CRYSTALLINE
UR - http://www.scopus.com/inward/record.url?scp=85052697857&partnerID=8YFLogxK
U2 - 10.1088/1361-6528/aad430
DO - 10.1088/1361-6528/aad430
M3 - Article
C2 - 30020078
AN - SCOPUS:85052697857
VL - 29
JO - Nanotechnology
JF - Nanotechnology
SN - 0957-4484
IS - 42
M1 - 425202
ER -
ID: 16319960