Electronic and optical properties of Mg-, F-doped and Mg∖F-codoped M 1 -VO 2 via hybrid density functional calculations

Abdellaoui, I.; Merad, G.; Mâaza, M.; Abdelkader, H. Si

doi:10.1016/j.jallcom.2015.10.248

Cited by 33 publications

(9 citation statements)

References 49 publications

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“…Figures c,d and S12 show the density of state and band structure of the VO 1.75 and VO 2 models. Fermi levels residing in the conduction band reveal the metallic character of VO 2 and VO 1.75 , which is in good agreement with the previous theoretical findings. , After introduction of V O •• , VO 1.75 exhibits a narrower bandgap than that of VO 2 , which agrees well with the valence band XPS results in Figures c,d. Zn ion diffusion energy barriers in VO 2 and VO 1.75 were calculated by simulating the Zn ions diffusion along the b tunnel (Figure e).…”

Section: Resultssupporting

confidence: 92%

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO₂

et al. 2020

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The aqueous zinc ion battery has emerged as a promising alternative technology for large-scale energy storage due to its low cost, natural abundance, and high safety features. However, the sluggish kinetics stemming from the strong electrostatic interaction of divalent zinc ions in the host crystal structure is one of challenges for highly efficient energy storage. Oxygen vacancies (VO ••), in the present work, lead to a larger tunnel structure along the b axis, which improves the reactive kinetics and enhances Zn-ion storage capability in VO2 (B) cathode. DFT calculations further support that VO •• in VO2 (B) result in a narrower bandgap and lower Zn ion diffusion energy barrier compared to those of pristine VO2 (B). VO ••-rich VO2 (B) achieves a specific capacity of 375 mAh g–1 at a current density of 100 mA g–1 and long-term cyclic stability with retained specific capacity of 175 mAh g–1 at 5 A g–1 over 2000 cycles (85% capacity retention), higher than that of VO2 (B) nanobelts (280 mAh g–1 at 100 mA g–1 and 120 mAh g–1 at 5 A g–1, 65% capacity retention).

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Section: Resultssupporting

confidence: 92%

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO₂

et al. 2020

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“…These parameters were in excellent agreement with available experimental observations (Goodenough, 1971;Zylbersztejn and Mott, 1975;Zhang, 2016) and theoretical studies (Wan et al, 2017;Chen et al, 2021). The calculated formation energy of the VO 2 (M) structure in this study by PBEsol (8.00 eV) was in fair agreement with other theoretical values using PBE + U approximation (7.14 eV), HSE functional (8.17 eV (Abdellaoui et al, 2016) and 7.18 eV (Zhang et al, 2011)), and the experimental value of 7.38 eV (Melnik et al, 2012;Lee et al, 2016), indicating that our method for semi-local XC functional calculation is reasonable.…”

Section: Analysis Of Geometry and Stabilitysupporting

confidence: 91%

Stability, phonon calculations, electronic structure, and optical properties of a VO2(M) nanostructure: A comprehensive density functional theory study

et al. 2023

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This work aimed to precisely evaluate the physical properties of vanadium dioxide (M), particularly the optical characteristics. We employed different exchange-correlation functionals to determine the phase stability, band gap properties, and optical characteristics of an experimentally recognized monoclinic VO2(M) polymorph. The calculations not only correctly interpreted the VO2(M) origin but also predicted other optical properties including the extinction coefficient (k) and refractive index (n), which have not been reported in experimental measurements. Phonon dispersion calculations confirmed the presence of negative frequencies for acoustic modes in the phononic curves. When the HSE functional correctly reproduced the experimental band gap, here for the first time, our calculations based on PBE and PBEsol yielded non-zero electronic bandgaps of 0.23 and 0.15 eV for bulk VO2(M). Our predictions showed that semi-local functionals can adequately predict the semiconductor properties of VO2(M) and performed better than all previously reported theoretical works on nulled band gaps. In addition to the better prediction of the peak position in the absorption spectra with HSE hybrid functional, this method also reasonably well described the static dielectric constant of 7.54, showing an excellent match to the experimental values. In general, the results of this study reveal that hybrid functionals yield superior outcomes compared to semi-local functionals for optical properties of a VO2(M) polymorph. Our results suggest that the PBEsol + HSE approach allows the efficient characterization of smart materials for electronic and optoelectronic applications.

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“…Among these dopants, tungsten is most effective, lowering T C by 20 °C per 1 at% [ 15 ]. VO 2 thin films can be co-doped with mixed metal ions, such as tungsten and molybdenum [ 23 ], tungsten and magnesium [ 24 ], and tungsten and fluorine [ 25 ]. A VO 2 thin film doped with lanthanum was prepared by Wang et al Below 3 at% La doping level, the band gap (E g ) decreased steadily with the increase of dopant concentration.…”

Section: Introductionmentioning

confidence: 99%

New intelligent multifunctional SiO₂/VO₂ composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity

Wang

Zhao

Liang

et al. 2017

Science and Technology of Advanced Materials

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Highly transparent, energy-saving, and superhydrophobic nanostructured SiO2/VO2 composite films have been fabricated using a sol–gel method. These composite films are composed of an underlying infrared (IR)-regulating VO2 layer and a top protective layer that consists of SiO2 nanoparticles. Experimental results showed that the composite structure could enhance the IR light regulation performance, solar modulation capability, and hydrophobicity of the pristine VO2 layer. The transmittance of the composite films in visible region (T lum) was higher than 60%, which was sufficient to meet the requirements of glass lighting. Compared with pristine VO2 films and tungsten-doped VO2 film, the near IR control capability of the composite films was enhanced by 13.9% and 22.1%, respectively, whereas their solar modulation capability was enhanced by 10.9% and 22.9%, respectively. The water contact angles of the SiO2/VO2 composite films were over 150°, indicating superhydrophobicity. The transparent superhydrophobic surface exhibited a high stability toward illumination as all the films retained their initial superhydrophobicity even after exposure to 365 nm light with an intensity of 160 mW.cm−2 for 10 h. In addition, the films possessed anti-oxidation and anti-acid properties. These characteristics are highly advantageous for intelligent windows or solar cell applications, given that they can provide surfaces with anti-fogging, rainproofing, and self-cleaning effects. Our technique offers a simple and low-cost solution to the development of stable and visible light transparent superhydrophobic surfaces for industrial applications.

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Electronic and optical properties of Mg-, F-doped and Mg∖F-codoped M 1 -VO 2 via hybrid density functional calculations

Cited by 33 publications

References 49 publications

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO₂

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO₂

Stability, phonon calculations, electronic structure, and optical properties of a VO2(M) nanostructure: A comprehensive density functional theory study

New intelligent multifunctional SiO₂/VO₂ composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity

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Electronic and optical properties of Mg-, F-doped and Mg∖F-codoped M 1 -VO 2 via hybrid density functional calculations

Cited by 33 publications

References 49 publications

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO2

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO2

Stability, phonon calculations, electronic structure, and optical properties of a VO2(M) nanostructure: A comprehensive density functional theory study

New intelligent multifunctional SiO2/VO2 composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity

Contact Info

Product

Resources

About

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO₂

Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO₂

New intelligent multifunctional SiO₂/VO₂ composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity