Surface oxidation of amorphous Si and Ge slanted columnar and mesoporous thin films: Evidence, scrutiny and limitations for infrared optics

Santos, Antonio J.; Lacroix, Bertrand; Maudet, Florian; Corvisier, Alan; Paumier, F.; Dupeyrat, Cyril; Girardeau, T.; Garcı́a, R.; Morales, F. M.

doi:10.1016/j.apsusc.2019.07.064

Cited by 10 publications

(4 citation statements)

References 46 publications

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“…This explanation supports the fact that the intensity of Cu 2 O peaks increases with the increase of the film thickness. Nonetheless, this phenomenon can also be result of spontaneous surface oxidation as a consequence of high surface/volume ratio after the samples were removed from the deposition chamber and exposed to air, as already reported in the literature [48].…”

Section: Resultssupporting

confidence: 51%

Optical properties of copper helical nanostructures: the effect of thickness on the SPR peak position

et al. 2022

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In this study, we have investigated the effect of thickness on the structural and optical properties of copper (Cu) helical nanostructures. Thin films with thicknesses of 160 nm, 280 nm, 450 nm, and 780 nm were obtained by e-beam glancing angle deposition. The morphology and the microstructure were studied by field emission scanning electron microscopy, X-ray diffraction and transmission electron microscopy, while for the optical analysis measurements spectroscopic ellipsometry was used. The results show that the deposited structures are porous with nanometer-sized crystallites preferentially oriented along (111) planes, as well as that the diameter of the helices increases with thickness. Detailed analyses of optical properties have demonstrated that the dielectric function of Cu structures is greatly influenced by the films thicknesses. With increasing thickness from 160 nm to 780 nm, the surface plasmon resonance (SPR) peak was shifted from 1.31 eV to 1.05 eV, which was correlated with the growth mechanism and the size of deposited nanostructures.

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Section: Resultssupporting

confidence: 51%

Optical properties of copper helical nanostructures: the effect of thickness on the SPR peak position

et al. 2022

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“…The insertion of porosity allows one to cut down the effective refractive index of the layer. However, increasing the porosity implies greater surface-to-volume ratios, which has been proven to have a detrimental effect on the electron mobility because the formation of native oxide shells within the semiconducting layers is favored when the surface exposed to air is greater . Hence, by tuning the growth conditions, the porosity of the nanostructures can be controlled, making these systems more appropriate for optical or electrical applications.…”

Section: Resultsmentioning

confidence: 99%

Simultaneous Optical and Electrical Characterization of GaN Nanowire Arrays by Means of Vis-IR Spectroscopic Ellipsometry

et al. 2019

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We report an original and straightforward method for both optical and electrical characterization of vertical GaN nanowire arrays epitaxially grown on silicon through visible-infrared spectroscopic ellipsometry methods. For the initial purpose of adding new inputs to the ellipsometry model, focused ion-beam tomography experiments were conducted to extract porosity/depth profiles of these systems. To reproduce the optical free-carrier behaviour in the infrared, the ellipsometric data acquired were fitted to an anisotropic Bruggeman model including Tauc-Lorentz and Drude oscillators, which

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“…On the basis of our previous studies, 43 porous V films with large surface-to-volume ratios and enhanced reactivity with oxygen were deposited by the GLAD technique. The deposition angle α (the average angle of incoming particle flux) relative to the substrate normal was set at α = 85° (the maximum inclination allowed for efficient GLAD deposition, so that the greater the deposition angle, the higher the overall porosity of the film and, therefore, its specific surface area 44 ) with no rotation of the substrate (i.e., ϕ = 0 rev h –1 ). Argon was injected at a mass flow rate of 2.40 sccm, and the pumping speed was maintained at S = 13.5 L s –1 , leading to a sputtering pressure of 0.3 Pa.…”

Section: Methodsmentioning

confidence: 99%

Facile Fabrication of High-Performance Thermochromic VO₂-Based Films on Si for Application in Phase-Change Devices

et al. 2023

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This work reports on an alternative and advantageous procedure to attain VO 2based thermochromic coatings on silicon substrates. It involves the sputtering of vanadium thin films at glancing angles and their subsequent fast annealing in an air atmosphere. By adjusting thickness and porosity of films as well as the thermal treatment parameters, high VO 2 (M) yields were achieved for 100, 200, and 300 nm thick layers treated at 475 and 550 °C for reaction times below 120 s. Comprehensive structural and compositional characterization by Raman spectroscopy, X-ray diffraction, and scanning-transmission electron microscopies combined with analytical techniques such as electron energy-loss spectroscopy bring to the fore the successful synthesis of VO 2 (M) + V 2 O 3 /V 6 O 13 /V 2 O 5 mixtures. Likewise, a 200 nm thick coating consisting exclusively of VO 2 (M) is also achieved. Conversely, the functional characterization of these samples is addressed by variable temperature spectral reflectance and resistivity measurements. The best results are obtained for the VO 2 /Si sample with changes in reflectance of 30−65% in the near-infrared at temperatures between 25 and 110 °C. Similarly, it is also proven that the achieved mixtures of vanadium oxides can be advantageous for certain optical applications in specific infrared windows. Finally, the features of the different structural, optical, and electrical hysteresis loops associated with the metal−insulator transition of the VO 2 /Si sample are disclosed and compared. These remarkable thermochromic performances hereby accomplished highlight the suitability of these VO 2 -based coatings for applications in a wide range of optical, optoelectronic, and/or electronic smart devices.

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Surface oxidation of amorphous Si and Ge slanted columnar and mesoporous thin films: Evidence, scrutiny and limitations for infrared optics

Cited by 10 publications

References 46 publications

Optical properties of copper helical nanostructures: the effect of thickness on the SPR peak position

Optical properties of copper helical nanostructures: the effect of thickness on the SPR peak position

Simultaneous Optical and Electrical Characterization of GaN Nanowire Arrays by Means of Vis-IR Spectroscopic Ellipsometry

Facile Fabrication of High-Performance Thermochromic VO₂-Based Films on Si for Application in Phase-Change Devices

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Surface oxidation of amorphous Si and Ge slanted columnar and mesoporous thin films: Evidence, scrutiny and limitations for infrared optics

Cited by 10 publications

References 46 publications

Optical properties of copper helical nanostructures: the effect of thickness on the SPR peak position

Optical properties of copper helical nanostructures: the effect of thickness on the SPR peak position

Simultaneous Optical and Electrical Characterization of GaN Nanowire Arrays by Means of Vis-IR Spectroscopic Ellipsometry

Facile Fabrication of High-Performance Thermochromic VO2-Based Films on Si for Application in Phase-Change Devices

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Product

Resources

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Facile Fabrication of High-Performance Thermochromic VO₂-Based Films on Si for Application in Phase-Change Devices