Influence of Thermal Annealings in Argon on the Structural and Thermochromic Properties of $$\mathrm{MoO}_{3}$$ MoO 3 Thin Films

Arvizu, Miguel A; Morales-Luna, M.; Pérez-González, M.; Campos‐González, E.; Zelaya-Ángel, O.; Tomás, S.A.

doi:10.1007/s10765-017-2190-1

Cited by 20 publications

(5 citation statements)

References 15 publications

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“…For MoO 3 thin films, the slight increase in E gap with the annealing temperature has also been observed by other groups, which have deposited this oxide by different synthesis techniques. − This effect has been associated with a structural rearrangement of the MoO 3 lattice, specifically a reduction of point defects . In addition, our group recently found that the crystallization process in MoO 3 takes place at higher temperatures, with respect to annealing in air, when the thermal treatments are performed in inert atmospheres. , This information implies that, for the SMC system, the CdSe layer causes a slow rearrangement process in the MoO 3 lattice as compared to the case where MoO 3 is directly exposed to oxygen. For all of the irradiated samples, the band-gap energy remains essentially constant (see Figure b).…”

Section: Resultssupporting

confidence: 63%

“…30 In addition, our group recently found that the crystallization process in MoO 3 takes place at higher temperatures, with respect to annealing in air, when the thermal treatments are performed in inert atmospheres. 25,33 This information implies that, for the SMC system, the CdSe layer causes a slow rearrangement process in the MoO 3 lattice as compared to the case where MoO 3 is directly exposed to oxygen. For all of the irradiated samples, the band-gap energy remains essentially constant (see Figure 7b).…”

Section: Resultsmentioning

confidence: 99%

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Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO₃ Thin Films Deposited by Physical Vapor Deposition

et al. 2019

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The influence of a cadmium selenide (CdSe) layer on the thermochromic and photochromic properties of molybdenum trioxide (MoO 3 ) thin films was studied. The films were deposited on glass substrates by thermal evaporation in vacuum using two different bilayer configurations, namely, substrate/MoO 3 /CdSe (SMC) and substrate/CdSe/MoO 3 (SCM). The film thicknesses for the MoO 3 and CdSe layers were ca. 250 and 20 nm, respectively. The thermochromic effect was evaluated in the annealing temperature range from 25 to 225 °C, in the presence of air. The characteristic optical absorption band attributed to the color center formation, centered at 820 nm, indicated enhanced thermo-and photochromic effects for both bilayer systems relative to monolayer MoO 3 thin films. For the thermochromic effect, this improvement was more pronounced when CdSe was the upper layer, i.e., for the SMC system. Regarding the photochromic effect, the films were irradiated with UV light for several exposure times within the lapse of 30−180 min. While both bilayer systems presented better photochromic response than pure MoO 3 thin films, the SCM system exhibited better photochromic response. These results are explained in terms of the optical, structural, and surface chemistry properties of the films.

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Section: Resultssupporting

confidence: 63%

Section: Resultsmentioning

confidence: 99%

Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO₃ Thin Films Deposited by Physical Vapor Deposition

et al. 2019

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“…According to the obtained results, the intensification of the SPR signal could be attributed to the presence of these three properties. In previous works has been demonstrated that the β -phase has a sub-stoichiometric amorphous structure associated with oxygen vacancies in the MoO 3 matrix 30,44 unlike the α -phase where its crystalline domain is bigger and available oxygen vacancies are less than β -phase 44 . The importance of oxygen vacancies to explain the increase in the SPR signal is of the utmost importance since these vacancies would function as electron traps, which could be absorbed the generated resonant electrons.…”

Section: Analysis and Resultsmentioning

confidence: 99%

Effective medium theory to the description of plasmonic resonances: Role of Au and Ti nanoparticles embedded in MoO3 thin films

Morales-Luna

2020

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The growing interest in functional transition metal oxides for efficient energy consumption or in the bio-sensing process; indicates that is necessary to develop a new theoretical method that describes experiments. This article presents a new theoretical methodology to characterize molybdenum trioxide (MoO 3) thin films doped with resonant gold-nanoparticles (Au-NPs) and non-resonant titaniumnanoparticles (Ti-NPs). The modulation of surface plasmon resonance (SPR) and the implications in the MoO 3 transmittance spectrum is described by applying an effective medium theory. The transmittance modulation was modified by variating three parameters, the radius of the NPs, the concentration of the NPs as well as the variation of the MoO 3 thin films thickness. It was found that the nanoparticles concentration is the most important parameter in the transmittance modulation. Additionally, the orthorhombic and monoclinic structure of MoO 3 was studied, from which it was obtained that the monoclinic structure of the MoO 3 doped with Au-NPs favors the reduction in the transmittance values in the visible region which is associated with the increase of the SPR signal. Similar analyses are performed for non-resonant nanoparticles such as Ti, where it was found that optical modulation is not as marked as the case of gold nanoparticles. Optical properties of different kind of systems has attracted attention for many researchers around the world 1-5. Developing new devices with interesting optical properties has been a technological and experimental challenge 6,7. In order to describe optical properties from a theoretical point of view, it have been developed sophisticated multiphysics modeling finite element commercial software, such as Comsol Multiphysics, Lumerical FDTD or BEM which allow you to calculate, reflection or transmission frequency-dependent or scattering parameters and near or far electromagnetic field projections. However, many of them are difficult to access since they are expensive or they are not very intuitive software's. So, implementing new theoretical formalisms to characterized and analyzed thin films with new, interesting and unexpected effects could be useful for developing new devices with different kinds of optical properties. There are some different approaches to characterize thin films 8-10 , particularly for thin films doped with different materials, using an effective medium theory to describe the radiation interaction with the doped thin films could be an alternative. In effective medium models, one of the most important approximation is the large size limit. The most studied formalisms that consider effective medium theories (EMTs) are Maxwell Garnett or Bruggeman, these models are applied to described materials with granular topology 11 and materials with intermixed components 12 , respectively. These EMTs are based on small spheres approximation, which means that the size of the particles is small compared with the incident radiation wavelength 13. An alternative formalism to study effective me...

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“…The sample deposited with the flow rate ratio of 0.48 O 2 /Ar showed a broadened band, centered at 2θ ≈ 35

, which suggested a coexistence between an amorphous structure and some few nanocrystallites dispensed in the matrix. At the flow rate ratio of 0.56 O 2 /Ar, corresponding to the second series of depositions, the diffractogram pattern showed in Figure 1 b, with broadband centered at 2θ ≈ 25

, confirmed the formation of an amorphous structure based on the MoOx units [ 38 , 39 , 40 ]. In the samples grown in silicon, the intensity of the peak corresponding to silicon was observed only on samples with sputtering time below 60 min, which inferred a lower sample thickness.…”

Section: Resultsmentioning

confidence: 92%

Molybdenum Oxide Thin Films Grown on Flexible ITO-Coated PET Substrates

et al. 2021

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Molybdenum oxide thin films were deposited on stiff and flexible substrates by reactive DC magnetron sputtering. Two sets of samples were prepared. The first with different O2/Ar flow rate ratios and the second, fixing the oxygen content, with different time of deposition. As the O2/Ar flow rate ratio varies from 0 up to 0.56, a threshold was found, ranging from crystalline to amorphous nature, and from a nontransparent appearance with metallic-like electrical conductivity to transparent and dielectric behaviour. From the second set, all transparent, the MoOx films present a compact/dense and featureless morphology with thickness from 190 up to 910 nm, depending on the time of deposition. Their structure was corroborated by XPS and Rutherford Backscattering Spectrometry (RBS) and density measurements were performed by RBS and X-ray reflectivity (XRR), revealing a value of 2.4 g/cm3. The surface roughness is in the order of a few nanometers and the maxima optical transmission, in the visible range, is around 89%. Electrochemical cyclic voltammograms showed noticeable color reversibility and reproducibility on the flexible substrates opening new framework possibilities for new electrochomic devices.

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Influence of Thermal Annealings in Argon on the Structural and Thermochromic Properties of $$\mathrm{MoO}_{3}$$ MoO 3 Thin Films

Cited by 20 publications

References 15 publications

Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO₃ Thin Films Deposited by Physical Vapor Deposition

Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO₃ Thin Films Deposited by Physical Vapor Deposition

Effective medium theory to the description of plasmonic resonances: Role of Au and Ti nanoparticles embedded in MoO3 thin films

Molybdenum Oxide Thin Films Grown on Flexible ITO-Coated PET Substrates

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Influence of Thermal Annealings in Argon on the Structural and Thermochromic Properties of $$\mathrm{MoO}_{3}$$ MoO 3 Thin Films

Cited by 20 publications

References 15 publications

Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO3 Thin Films Deposited by Physical Vapor Deposition

Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO3 Thin Films Deposited by Physical Vapor Deposition

Effective medium theory to the description of plasmonic resonances: Role of Au and Ti nanoparticles embedded in MoO3 thin films

Molybdenum Oxide Thin Films Grown on Flexible ITO-Coated PET Substrates

Contact Info

Product

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Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO₃ Thin Films Deposited by Physical Vapor Deposition

Effect of a CdSe Layer on the Thermo- and Photochromic Properties of MoO₃ Thin Films Deposited by Physical Vapor Deposition