Recent advance in phase transition of vanadium oxide based solar reflectors and the fabrication progress

Mirbagheri, Golsa; Crouse, David T.; Tan, Chee-Keong

doi:10.1117/12.2626406

Cited by 4 publications

(2 citation statements)

References 18 publications

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“…Other methods using reactive DC magnetron sputtering (Song and White, 2016;Mirbagheri et al, 2022) are still to be performed since this deposition needs annealing at around 500 °C of the VO 2 . Victor et al (2021) succeeded to deposit the W doped VO 2 tunable around room temperature for smart radiator applications.…”

Section: Deposition Methodsmentioning

confidence: 99%

Review of the VO2 smart material applications with emphasis on its use for spacecraft thermal control

et al. 2022

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It is surprising to see the wide range and versatile potential of applications of the VO2, due to its transition from a semiconductor phase at low temperature, to a metallic state at high temperature. Although this transition’s atomic mechanism is not yet well understood, the tuneability is very reproducible experimentally and can be monitored by various triggering schemes, not only by heating/cooling but also by applying a voltage, pressure, or high power single fast photonic pulse. Many of the recent applications use not only the low-temperature phase and the high-temperature phase, but also the transition slope to monitor a specific parameter. The paper starts with a summary of the VO2 thin film deposition methods and a table presenting its recent proposed applications, some of which our team had worked on. Then the development characterization and application of the VO2 as a smart thermal radiator is provided along with the recent progress. The experimental results of the emissivity were measured at low temperature and high temperature, as well as during the transition in vacuum based on the thermal power balance. These measurements were compared with those deduced from an average of Infrared Reflectance (2–30 µm) weighed with the blackbody reflection spectrum. The roadmap is to try alternatives of the multilayers in order to increase the emissivity tuneability, increase the device dimensions, have an easier application on space surfaces, while lowering cost.

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Section: Deposition Methodsmentioning

confidence: 99%

Review of the VO2 smart material applications with emphasis on its use for spacecraft thermal control

et al. 2022

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“…Additionally, the mechanical properties of the composite thin film are investigated by regulating the UV and green lights, resulting in a slight nanoscale bending actuation due to isomerization of the AAP molecules embedded in the polymer matrix. Tunable subwavelength materials enable changing the light-matter interactions could be used in novel applications including sensing and imaging applications [19,20,21].…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of the propagation modes of photo-switching PDMS-arylazopyrazole optical waveguide and thin-film spectroscopic characterization

Mirbagheri

Uba

Ghebreyessus

et al. 2023

Integrated Optics: Devices, Materials, and Technologies XXVII

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A new light responsive arylazopyrazole (AAP) containing polymer matrix thin film is fabricated by spincoating of different concentrations of the AAP azo dye into the polydimethylsiloxane (PDMS) polymer at 150°C. The new AAP molecular switch was also used to fabricate a solid-state PDMS-AAP waveguide by contact lithography and soft replica modeling methods in the micrometer scale. The refractive index of the spin-coated photoswitchable material can be modulated via the reversible trans-to-cis photoisomerization behavior of the AAP unit using different concentrations. When 0.01 M solution of the AAP unit was used, the refractive of the composite was 2.32 in the trans state and dropped to 1.85 in the cis state in the operating wavelength of 340 nm. At higher concentrations of 0.020 and 0.03 M, a wide refractive index tuning is achieved under the same wavelength. In 0.030 M the refractive index was 2.65 for the trans state and 2.0 for the cis state. The results suggest that the increase in refractive index tuning is related to the concentration of the AAP unit of the composite film. Theoretically, the spectral properties of the composite film are also simulated with two methods: 1) the Maxwell Equations; and 2) the frequency dependent finite element, showing excellent agreement for the different propagation modes of the proposed waveguide for regulated signals of 365/525 nm wavelengths. Furthermore, the photoisomerization of the PDMS-AAP thin film is analyzed with UV-vis spectroscopy to demonstrate the isomerization responses of the AAP moiety in the solid state. Additionally, preliminary photomechanical actuation properties of the composite film have been investigated. The PDMS-AAP waveguide described in this study provides a new approach for optically tunable photonics applications in the Visible-IR region.

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Design, fabrication, and spectral characterization of temperature-dependent liquid crystal-based metamaterial to tune dielectric metasurface resonances

Mirbagheri

Crouse

2022

Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XV

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Recent advance in phase transition of vanadium oxide based solar reflectors and the fabrication progress

Cited by 4 publications

References 18 publications

Review of the VO2 smart material applications with emphasis on its use for spacecraft thermal control

Review of the VO2 smart material applications with emphasis on its use for spacecraft thermal control

Numerical analysis of the propagation modes of photo-switching PDMS-arylazopyrazole optical waveguide and thin-film spectroscopic characterization

Design, fabrication, and spectral characterization of temperature-dependent liquid crystal-based metamaterial to tune dielectric metasurface resonances

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