A flexible, multifunctional, active terahertz modulator with an ultra-low triggering threshold

Ma, He; Wang, Yu; Rong, Lü; Tan, Fangzhou; Fu, Yulan; Wang, Guang; Wang, Dayong; Li, Kai; Fan, Shanhui; Jiang, Kaili

doi:10.1039/d0tc02446e

Cited by 18 publications

(16 citation statements)

References 49 publications

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“…Vanadium dioxide (VO 2 ) undergoes a reversible metal-to-insulator phase transition (MIT) at a critical temperature ( T MIT ) of 68 °C between insulating monoclinic VO 2 (M 1 ) with high THz transparency and metallic rutile VO 2 (R) with strong THz absorbance and reflection. , This ultrafast (<80 fs) phase transition also involves sharp changes in electrical resistance and can be triggered by various types of stimuli, including thermal heating, electrical current excitation, light irradiation, and mechanical strain. Such unique properties make VO 2 films promising candidates for the role of active medium in tunable THz amplitude modulators, switches, tunable absorbers, emitters, photonic crystals, and metamaterials . To improve the performance of THz switches and modulators, it is necessary to achieve a large THz modulation depth (MD), low insertion loss and MIT temperature, providing a low thermal/optical trigger threshold.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Epitaxial W-Doped VO₂ Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Ivanov

Tatarenko

Gorodetsky

et al. 2021

ACS Appl. Nano Mater.

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We report a feasible and high-throughput method for high-quality W-doped VO 2 nanostructured epitaxial films on rsapphire substrate fabrication. Single-phase, smooth vanadium dioxide thin films with uniform distribution of tungsten (up to 2.3%) are formed using the solvothermal process from ethylene glycol/water V 4+ and W 6+ solutions. Compositional analysis by X-ray photoelectron and energy-dispersive X-ray spectroscopy (XPS and EDX, respectively); structural analysis (X-ray diffraction, Raman spectroscopy, selected area electron diffraction (SAED)); and detailed analysis of the surface morphology and substrate−film interface using scanning electron microscopy, atomic force microscopy, and high-resolution transmission electron microscopy (SEM, AFM, HRTEM, respectively) confirm the formation of nanoscale (50−60 nm) epitaxial W:VO 2 (M 1 ) on r-sapphire with epitaxial relationships (100)VO 2 ∥(101̅ 2)Al 2 O 3 and [010]VO 2 ∥[011̅ 0]Al 2 O 3 . The nanostructured films demonstrate excellent terahertz (THz) transmission properties: a phase transition temperature of 31 °C, a huge THz modulation depth of over 60%, and broad bandwidth (≥2 THz) operation. Hence, they can be efficiently used as active material for tunable THz manipulation devices.

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Section: Introductionmentioning

confidence: 99%

Fabrication of Epitaxial W-Doped VO₂ Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Ivanov

Tatarenko

Gorodetsky

et al. 2021

ACS Appl. Nano Mater.

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“…Flexible VO 2 /CNT THz modulator has been achieved by fabricating VO 2 on aligned carbon nanotube (CNT) films, which could be driven by various stimuli. 38 With increasing temperature, the VO 2 /CNT shows a significant reduction of the transmission amplitude at 2 THz (Figure 2G). Meanwhile, the VO 2 /CNT THz modulator could be triggered by an electrothermal effect when voltage is applied on the CNT substrate (Figure 2H).…”

Section: Flexible Vo 2 Optical Devicesmentioning

confidence: 99%

Section: Flexible Vo2 Optical Devicesmentioning

confidence: 99%

“…Besides the modulation of IR radiation, VO 2 possesses excellent modulation ability of terahertz (THz) waves (30–3000 μm), which ranges from the infrared to the microwave region. Flexible VO 2 /CNT THz modulator has been achieved by fabricating VO 2 on aligned carbon nanotube (CNT) films, which could be driven by various stimuli . With increasing temperature, the VO 2 /CNT shows a significant reduction of the transmission amplitude at 2 THz (Figure G).…”

Section: Flexible Vo2 Optical Devicesmentioning

confidence: 99%

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Multifunctional Flexible Vanadium Dioxide Films

et al. 2021

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Conspectus As a typical phase transition material, vanadium dioxide (VO2) has attracted much attention due to its amazing metal–insulator transition (MIT) at the critical temperature of 68 °C, which could be driven by multiple stimuli, including electricity, thermal irradiation, THz waves, strain, etc. In the MIT process, VO2 exhibits significant changes in its structure from monoclinic structure at low temperature to rutile structure at high temperature, accompanied by significant modulation of physical properties, such as the infrared transmittance from high to low and a resistivity drop over 5 magnitudes. Based on these features, VO2 has functioned as thermochromic coatings, sensors, switches, electronic devices, actuators, etc. However, the vanadium element possesses multiple valent states and can produce complicated thermodynamics of vanadium oxides. The fabrication of tetravalence VO2 with desirable phase-transition features usually requires rigorous fabrication conditions with a precisely controlled atmosphere for stoichiometric components and high temperatures for good crystallinity. Under these circumstances, it is difficult to directly fabricate crystalline VO2 films on flexible polymer substrates because most of them could not stand such high temperatures (usually >400 °C), which will lead to the loss of the substrate functionality. However, the featured phase transition of VO2 makes it a promising candidate for future flexible devices, while VO2 owns great potential as flexible optical coatings, flexible sensors, flexible electronics, etc. Hence, research on flexible VO2 films is necessary and could largely pave the way to the application field of VO2 material. In this Account, we start with a brief introduction to phase transition properties of VO2 to reveal the intrinsic advantages as key materials in flexible devices. Next, multifunctional devices based on flexible VO2 films with different forms and characteristics are presented, including (1) flexible VO2-film-based thermochromic smart windows for energy-saving function depending on the change of environmental temperatures, (2) flexible VO2 films optical devices based on the changing emissivity of VO2, (3) flexible VO2 films with compatibility as multifunctional sensors, (4) next-generation flexible electronics based on VO2 films, and (5) flexible VO2 actuators with significant mechanical motions under external stimuli. Meanwhile, various fabrication technologies of flexible VO2 films have been introduced and discussed. Finally, we end the Account with an overview of the remaining challenges and new opportunities that have been opened up for vanadium dioxide in new forms of flexible optical and electronic devices. We hope this Account will inspire new innovative designs, fabrication approaches, and more possible functions of flexible VO2 films in future work.

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“…Recent developments in preparing macroscopic films of highly ordered, or aligned CNTs in film or fiber form [21][22][23][24][25][26][27][28] have enabled fundamental studies of 1D physics as well as development of unique 1D devices on a macroscopic scale [13,14]. For example, strong optical anisotropy has resulted in CNT-based polarizers [21,[29][30][31], polarization rotators [32], and modulators [33][34][35][36]. Metallic and doped aligned CNT films are natural hyperbolic materials [37][38][39], in which the epsilon near point is located in the infrared and can be tubed by doping [40].…”

Section: Introductionmentioning

confidence: 99%

Carbon Nanotube Devices for Quantum Technology

et al. 2022

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Carbon nanotubes, quintessentially one-dimensional quantum objects, possess a variety of electrical, optical, and mechanical properties that are suited for developing devices that operate on quantum mechanical principles. The states of one-dimensional electrons, excitons, and phonons in carbon nanotubes with exceptionally large quantization energies are promising for high-operating-temperature quantum devices. Here, we discuss recent progress in the development of carbon-nanotube-based devices for quantum technology, i.e., quantum mechanical strategies for revolutionizing computation, sensing, and communication. We cover fundamental properties of carbon nanotubes, their growth and purification methods, and methodologies for assembling them into architectures of ordered nanotubes that manifest macroscopic quantum properties. Most importantly, recent developments and proposals for quantum information processing devices based on individual and assembled nanotubes are reviewed.

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A flexible, multifunctional, active terahertz modulator with an ultra-low triggering threshold

Abstract: Flexible, multifunctional, active THz modulators with ultra-low triggering threshold were developed by aligned carbon nanotube thin films coated with VO2. These active THz modulators find applications in THz communication and THz imaging.

Cited by 18 publications

References 49 publications

Fabrication of Epitaxial W-Doped VO₂ Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Fabrication of Epitaxial W-Doped VO₂ Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Multifunctional Flexible Vanadium Dioxide Films

Carbon Nanotube Devices for Quantum Technology

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A flexible, multifunctional, active terahertz modulator with an ultra-low triggering threshold

Abstract: Flexible, multifunctional, active THz modulators with ultra-low triggering threshold were developed by aligned carbon nanotube thin films coated with VO2. These active THz modulators find applications in THz communication and THz imaging.

Cited by 18 publications

References 49 publications

Fabrication of Epitaxial W-Doped VO2 Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Fabrication of Epitaxial W-Doped VO2 Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Multifunctional Flexible Vanadium Dioxide Films

Carbon Nanotube Devices for Quantum Technology

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Product

Resources

About

Fabrication of Epitaxial W-Doped VO₂ Nanostructured Films for Terahertz Modulation Using the Solvothermal Process

Fabrication of Epitaxial W-Doped VO₂ Nanostructured Films for Terahertz Modulation Using the Solvothermal Process