Strain Effects in Epitaxial VO2 Thin Films on Columnar Buffer-Layer TiO2/Al2O3 Virtual Substrates

Breckenfeld, Eric; Kim, Heung Soo; Burgess, Katherine; Charipar, Nicholas A.; Cheng, Shuo; Stroud, Rhonda M.; Piqué, Alberto

doi:10.1021/acsami.6b13112

Cited by 50 publications

(37 citation statements)

References 41 publications

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“…The differences to the TG results could be explained by a substrate mediated strain-effects for the silicon substrates, which is known to reduce the transition temperature as well as reducing the hysteresis, probably due to surface oxidation of the VO2 layer. [45,46] 14 The spectra displayed the typically two-peak structure (2 p3/2 and 2 p1/2) due to the spinorbit splitting. The binding energies decreased with lower oxidation state of the vanadium atom.…”

Section: Space Group P1 P1mentioning

confidence: 98%

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO₂ and V₂O₃ Nanostructures

et al. 2017

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Section: Space Group P1 P1mentioning

confidence: 98%

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO₂ and V₂O₃ Nanostructures

et al. 2017

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“…On the other hand, τ c of VO 2 has to be reduced for room temperature applications together with insufficient NIR regulating capability . Currently there are a few methods to address these two issues, i.e., chemical doping, nano‐thermochromism, nanoporous structure, core–shell structure, multilayered structure, and so forth. In this paper, we proposed a facile VO 2 /carbon composite structure synthesised by plasma enhanced chemical vapor deposition (PECVD).…”

Section: Introductionmentioning

confidence: 99%

Largely Lowered Transition Temperature of a VO₂/Carbon Hybrid Phase Change Material with High Thermal Emissivity Switching Ability and Near Infrared Regulations

Wang

Liu

et al. 2018

Adv Materials Inter

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Vanadium oxide (VO2) as a phase changing material possesses abrupt infrared (IR) transmission and thermal emissivity changing during the metal–insulator transition across transition temperature (τc) of 68 °C. However, the high τc, moderate IR transmission and emissivity regulating ability limits its applications in various fields. A VO2/carbon hybrid phase change material fabricated via homemade plasma enhanced chemical vapor deposition is reported. The material shows a best reported thermal emissivity contrast (0.44) among the experimental values, a largely lowered τc (45 °C), promising a near IR‐regulation ability with enhanced photothermal effect in smart windows applications. The theoretical calculation results proved that the improvement of emissivity contrast is due to the hybridization of carbon. This work provides a new approach to synthesize VO2 hybrid materials, which have wide applications in camouflage, sensing, and smart windows.

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“…Strain can be uniformly introduced in large, planar areas (cm 2 ) by epitaxial growth of thin VO 2 films on closely lattice matched substrates such as TiO 2 (001). Strain introduced in this manner has been demonstrated to reduce the transition temperature, and experimental evidence suggests that the structural component of the IMT can be suppressed . Epitaxially strained VO 2 films thus provide a unique platform for investigating the basic physical properties of the phase transition as well as a means for engineering the material response.…”

Section: Introductionmentioning

confidence: 89%

“…Film Growth : VO 2 films were grown via pulsed‐laser deposition (Lambda Physik, 248 nm, 20 ns pulse width) from a stoichiometric target (ACI Alloys) on single crystalline TiO 2 (001) and c‐cut Al 2 O 3 (0001) substrates with an oxygen partial pressure of 12 mTorr at substrate temperatures of 400 and 550 °C, with nominal thicknesses of 8 and 60 nm for the strained and relaxed films, respectively. The target to substrate distance was held constant at 5 cm and the films were deposited with a laser fluence of 2 J cm −2 with a repetition rate of 5 Hz.…”

Section: Methodsmentioning

confidence: 99%

Ultrafast Phase Transition Dynamics in Strained Vanadium Dioxide Films

Suess

Bingham

Charipar

et al. 2017

Adv Materials Inter

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the material response. In the present work, an ultrafast optoelectronic autocorrelation technique is used to directly measure the dynamical electrical properties of epitaxially strained VO 2 across the IMT. This approach differs from purely optical methods, such as pump-probe measurements, where electrical properties of the material must be inferred from reflected or transmitted light. While the optoelectronic autocorrelation technique uses a combination of optical excitation and electrical sensing, the method differs significantly from purely electrical VO 2 switching measurements that use high-amplitude voltage pulses to initiate the IMT. Purely electrical switching experiments have a relatively low temporal resolution due to the electrical readout, which is typically limited to nanosecond time scales. [11][12][13][14] The findings reported here show it is possible to transiently induce an insulator-metal-insulator phase transition cycle over a time interval less than 400 fs with a measured change in signal spanning two orders in magnitude. These dynamics contrast those of relaxed VO 2 , which typically exhibits a prolonged metallic phase that persists for nanoseconds after pulsed optical excitation. [15,16] Isolating solely the role of strain is challenging as differences in film thickness and morphology may also influence the material response. Nevertheless, the ultrafast response observed in the strained film suggests it may be possible to selectively activate the metallic phase without inducing a change in crystalline structure. Our findings are discussed within the context of recent findings that report a suppressed structural phase transition (SPT) in strained VO 2 [10,17] as well as works that consider intermediate states that separate the IMT and SPT. [18,19] These results have promising implications for optical or optoelectronic devices where fast switching and modulation are required. Results and DiscussionThe films investigated in this work exhibit a temperaturedependent resistivity (Figure 1a) that demonstrates a clear IMT at a temperature, T IMT , of 341 and 296 K for relaxed and strained films, respectively. The relaxed films are oriented, single-phase VO 2 on c-cut Al 2 O 3 substrates and are used as a canonical material with a known electrical and SPT [3,4] against which the dynamical response of the strained films can be compared. The large shift in transition temperature for the strained film signifies the stabilization of the tetragonal phase due to the film adopting the lattice symmetry of the TiO 2 (001) substrate. [10] An ultrafast insulator-metal-insulator phase transition cycle in epitaxially strained vanadium dioxide films is observed. The films are characterized by optoelectronic autocorrelation measurements that reveal a 400 fs transient change in response spanning two orders in magnitude. These findings suggest a predominantly electronic mechanism and demonstrate the promise of this material for optoelectronic applications requiring fast, high-contrast switching.

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Strain Effects in Epitaxial VO₂ Thin Films on Columnar Buffer-Layer TiO₂/Al₂O₃ Virtual Substrates

Cited by 50 publications

References 41 publications

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO₂ and V₂O₃ Nanostructures

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO₂ and V₂O₃ Nanostructures

Largely Lowered Transition Temperature of a VO₂/Carbon Hybrid Phase Change Material with High Thermal Emissivity Switching Ability and Near Infrared Regulations

Ultrafast Phase Transition Dynamics in Strained Vanadium Dioxide Films

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Strain Effects in Epitaxial VO2 Thin Films on Columnar Buffer-Layer TiO2/Al2O3 Virtual Substrates

Cited by 50 publications

References 41 publications

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO2 and V2O3 Nanostructures

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO2 and V2O3 Nanostructures

Largely Lowered Transition Temperature of a VO2/Carbon Hybrid Phase Change Material with High Thermal Emissivity Switching Ability and Near Infrared Regulations

Ultrafast Phase Transition Dynamics in Strained Vanadium Dioxide Films

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Strain Effects in Epitaxial VO₂ Thin Films on Columnar Buffer-Layer TiO₂/Al₂O₃ Virtual Substrates

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO₂ and V₂O₃ Nanostructures

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO₂ and V₂O₃ Nanostructures

Largely Lowered Transition Temperature of a VO₂/Carbon Hybrid Phase Change Material with High Thermal Emissivity Switching Ability and Near Infrared Regulations