Study of the Absorptance of a Thin Layer of the Vanadium Dioxide

Chaib, Abderrahim Ben; Zouini, Mohammed; Zorkani, Izeddine; Mdaa, Abdesselam; Jorio, Anouar

doi:10.17485/ijst/2016/v9i48/100111

Cited by 5 publications

(3 citation statements)

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“…Unlike the range of optical frequencies, where ellipsometry (a far-field approach) is a powerful tool for the determination of the relative dielectric permittivity of the VO 2 , given by when thin films are deposited on different substrates, − near-field approach or conformal mapping are used in rf engineering of electronic functions.…”

Section: Introductionmentioning

confidence: 99%

Radio-Frequency Characteristics of Ge-Doped Vanadium Dioxide Thin Films with Increased Transition Temperature

Müller

Khadar

Abel

et al. 2020

ACS Appl. Electron. Mater.

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This work investigates and reports on the radio-frequency (rf) behavior in the frequency range of 5–35 GHz of germanium-doped vanadium dioxide (Ge-doped VO2) thin films deposited on silicon substrates via sputtering and pulsed laser deposition (PLD) with estimated Ge concentrations of 5 and 5.5%. Both films exhibit critical transition temperatures (T c) of 76.2 and 72 °C, respectively, which are higher compared to that of the undoped VO2 which undergoes reversible insulator-to-metal phase transition at 68 °C. Both types of Ge-doped films show low hysteresis (<5 °C) in their conductivity versus temperature characteristics and preserve high off-state dc-conductivities (corresponding to the insulating state of the phase change material) of 13 S/m for the sputtered and 55 S/m for the PLD-deposited film, respectively. The dc on-state (corresponding to the conductive state of the phase change material) conductivity reaches 145,000 S/m in the case of the PLD film, which represents a significant increase compared to the state-of-the art values measured for undoped VO2 thin films deposited on identical substrates. In order to further understand the off-state dissimilarities and rf behavior of the deposited Ge-doped VO2 films, we propose an original methodology for the experimental extraction of the dielectric constant (εr) in the GHz range of the films below 60 °C. This is achieved by exploiting the frequency shift of resonant filters. For this purpose, we have fabricated coplanar waveguide structures incorporating ultracompact Peano space-filling curves, each resonating at a different frequency between 5 and 35 GHz on two types of substrates, one with the Ge-doped VO2 thin films and another one using only SiO2 to serve as the reference. The reported results and analysis contribute to the advancement of the field of metal–insulator–transition-material technology with high T c for rf industrial applications.

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Section: Introductionmentioning

confidence: 99%

Radio-Frequency Characteristics of Ge-Doped Vanadium Dioxide Thin Films with Increased Transition Temperature

Müller

Khadar

Abel

et al. 2020

ACS Appl. Electron. Mater.

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show abstract

“…He highlighted its reversible phase transition [19][20][21][22][23][24][25] from the semiconductor state to its metal state at a transition temperature Tc = 68°C. This phase transition then generates the changes of the optical properties of this material [26][27][28][29][30] within the infra-red range. Within this framework, one observes an important variation in the transmission of VO2 film between the insulating state, characterized by a high transmission (42% at 5°C), and the metal state, where the transmission is very weak (5% at 100°C).…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of Various Thermal Analyses of Smart Windows in Cubic Building Design

Khattabi¹,

Mharzi²,

Zouini³

et al. 2018

JESTR

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This paper presents a thermal analysis of compounds called smart windows in typical building design; such windows are covered with a vanadium dioxide film doped with tungsten and are characterized by their phase transition which makes the transmission coefficient high for low temperatures and low for high temperatures. This leads to the natural optimization of thermal comfort in summer and winter through a decrease in solar radiation transmission in the summer and an increase in it in the winter. A comparative study of four types of glass has been carried out both in summer and winter: simple glass SiO2, dioxide of vanadium un-doped glass, vanadium dioxide glass doped with 3% tungsten and 5% tungsten in order to evaluate their effect on the interior temperature of the building. For these reasons, a thermal model in the dynamic state has been developed to assess the thermal performance in such a building and to evaluate the effect of these windows on thermal comfort in terms of heat flow, density and internal temperature. The analysis was carried out having taken into account the external weather conditions of Fez, such as radiation, natural convection, air exchange, and the outdoor temperature as well as different parameters of the building envelope.

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“…This phase transition causes enormous changes in the optical and electrical properties of this material [14][15][16][17][18] in the near infrared. Below the transition temperature the resistivity [19] decreases exponentially as the temperature increases.…”

Section: Introductionmentioning

confidence: 99%

Information Restitution in the Optical Memories using a Thin Layer of the Vanadium Dioxide

Zouini¹,

Chaib²,

Mdaa³

et al. 2018

JESTR

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Today, nanotechnologies have become a very important part of our daily life, contributing to the significant improvement of many technological and industrial sectors such as information technology, internal security, medicine, transport, energy, food safety, environmental sciences and many others. This technology allows materials to be processed at the nanoscale. We have studied the vanadium dioxide VO2, a material that is currently being researched in the development of new technologies, and the possibility of integrating nanoparticles of this material into the energy field, knowing that it's considered an intelligent material. Each cooling followed by heating of such a material generates a hysteresis loop, the area of this loop represents the energy dissipated in this material. In this paper, we will mathematically model this loop to determine the dissipated energy E that can be reduced or reused as an energy source. We compared the energy dissipated in pure vanadium dioxide and doped according to the two types of doping n-type with 5% tungsten (W), p-type with 15% chromium (Cr), we find that doping in general results in a decrease in the energy dissipated in this material compared to the pure state.

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Study of the Absorptance of a Thin Layer of the Vanadium Dioxide

Cited by 5 publications

References 0 publications

Radio-Frequency Characteristics of Ge-Doped Vanadium Dioxide Thin Films with Increased Transition Temperature

Radio-Frequency Characteristics of Ge-Doped Vanadium Dioxide Thin Films with Increased Transition Temperature

Comparative Study of Various Thermal Analyses of Smart Windows in Cubic Building Design

Information Restitution in the Optical Memories using a Thin Layer of the Vanadium Dioxide

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