Optical parameters and energy gap estimation in hafnia thin film

Shilov, A. O.; Savchenko, S. S.; Вохминцев, А. С.; Gritsenko, V. A.; Weinstein, I. A.

doi:10.1063/5.0033176

Cited by 5 publications

(6 citation statements)

References 13 publications

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“…Nevertheless, the obtained E g value is in agreement with other independent data. In particular, for HfO 2 thin films of produced by ion beam sputtering deposition method E g = 5.4 ± 0.05 eV [6]. For the films synthesized using atomic-layer deposition technique energy gap value is 5.55 eV [7].…”

Section: Discussionmentioning

confidence: 98%

“…Along with the other IVB metal oxides (ZrO 2 , TiO 2 ) HfO 2 is considered to be a promising solid-state medium for creation of the non-volatile memory cells because of its physical properties and favorable valence and conduction band alignments [1][2][3][4][5]. Due to wide energy gap and high refractive index hafnia is used as optical coatings [6]. As downscaling of field effect transistors has become difficult, HfO 2 could also be a candidate to replace SiO 2 as gate dielectric [7].…”

Section: Introductionmentioning

confidence: 99%

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Energy Gap Evaluation in Microcrystalline m-HfO2 Powder

Shilov

Savchenko

Вохминцев

et al. 2021

Journal of Siberian Federal University. Mathematics &Amp; Physics

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In this paper optical properties of microcrystalline HfO2 powder are investigated. X-ray diffraction and Raman spectroscopy were used to determine that the studied samples are in monoclinic phase. Based on the analysis of the diffuse reflectance spectra and applying Kubelka-Munk formalism we evaluated the indirect bandgap value Eg = 5.34 ± 0.05 eV. The calculated value is in agreement with independent data for HfO2 thin films synthesized by various methods. The paper is based on the materials of the report presented at the first Russian scientific confererence with the participation of the international community "YENISEI PHOTONICS – 2020"

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Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Energy Gap Evaluation in Microcrystalline m-HfO2 Powder

Shilov

Savchenko

Вохминцев

et al. 2021

Journal of Siberian Federal University. Mathematics &Amp; Physics

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“…Manipulating the morphology of the synthesized oxide layer-solid → porous → nanotubular-can be performed by varying both the electrolyte composition and parameters of electrochemical synthesis, such as a voltage between the electrodes, current flowing through the solution, oxidation time, and temperature [16]. In turn, the geometric parameters and phase composition of NTs have a dramatic influence on the features of their electronic subsystem and various structure-sensitive capabilities [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Luminescence in Anion-Deficient Hafnia Nanotubes

Shilov,

Kamalov,

Karabanalov

et al. 2023

Nanomaterials

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Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronic devices. They possess a unique combination of physical and chemical properties, such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric HfO2 nanotubes. As-grown amorphous hafnia nanotubes and nanotubes annealed at 700 °C with a monoclinic crystal lattice served as samples. It has been shown that the bandgap Eg for direct allowed transitions amounts to 5.65 ± 0.05 eV for amorphous and 5.51 ± 0.05 eV for monoclinic nanotubes. For the first time, we have studied the features of intrinsic cathodoluminescence and photoluminescence in the obtained nanotubular HfO2 structures with an atomic deficiency in the anion sublattice at temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3–2.4 eV has been revealed. We have also conducted an analysis of the kinetic dependencies of the observed photoluminescence for synthesized HfO2 samples in the millisecond range at room temperature. It showed that there are several types of optically active capture and emission centers based on vacancy states in the O3f and O4f positions with different coordination numbers and a varied number of localized charge carriers (V0, V−, and V2−). The uncovered regularities can be used to optimize the functional characteristics of developed-surface luminescent media based on nanotubular and nanoporous modifications of hafnia.

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“…Moreover, there are widespread methods to synthesize HfO 2 thin films supported on quartz and silicon substrates by atomic layer deposition and magnetron sputtering [9,[17][18][19][20][21]. However, the low-dimensional structures obtained in such a way are, as a rule, amorphous and crystallize only after hightemperature annealing [9,22].…”

Section: Introductionmentioning

confidence: 99%

“…Despite the availability of samples with different morphologies to test, the literature chiefly comprises data on luminescence for HfO 2 films doped with ions of various chemical elements [9,12,17,[21][22][23][24][25]. In this context, the properties of luminescent nominally pure structures still remain largely unexplored.…”

Section: Introductionmentioning

confidence: 99%