Article
Multidisciplinary Sciences
Jiyu Xu, Daqiang Chen, Sheng Meng
Summary: Photoexcitation has been proven as an efficient way to trigger phase transitions in strongly correlated materials. However, the atomistic mechanisms behind the structural phase transitions (SPTs) and electronic insulator-metal transitions (IMTs) in VO2 have been controversial. This study clarifies some key controversies and provides insights into the underlying atomistic processes and decoupling nature of photoinduced SPT and IMT in nonequilibrium states.
Article
Chemistry, Multidisciplinary
Mengxia Qiu, Wanli Yang, Peiran Xu, Tiantian Huang, Xin Chen, Ning Dai
Summary: This study presents polymorphous VO2 thin films with coexistent VO2 (M) and VO2 (B) phases and phase-dependent insulator-metal transition (IMT) behaviors. The presence of VO2 (B) phases may induce lattice distortions in VO2 (M), resulting in widened plane spacing of (011)(M) in the VO2 (M) phase and shifted V-V and V-O vibrations. The coexisting VO2 (B) phases promote the IMT temperature of the polymorphous VO2 thin films.
Article
Chemistry, Physical
Dooyong Lee, Taewon Min, Jiwoong Kim, Sehwan Song, Jisung Lee, Haeyong Kang, Jouhahn Lee, Deok-Yong Cho, Jaekwang Lee, Jae Hyuck Jang, Sungkyun Park
Summary: The study found that octahedral symmetry in VO2 can control its IMT characteristics by changing orbital occupancy, and monoclinic VO2 with high octahedral symmetry exhibits bandwidth-controlled IMT characteristics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Coatings & Films
Chengyang Zhang, Ravindra Singh Bisht, Amin Nozariasbmarz, Arnob Saha, Chan Su Han, Qi Wang, Yifan Yuan, Abhronil Sengupta, Shashank Priya, Shriram Ramanathan
Summary: VO2 thin films were successfully grown on different substrates and their crystal structure and chemical composition were analyzed using X-ray diffraction and X-ray photoelectron spectroscopy. The films exhibited metal-insulator transition under temperature and electric field, which is of great importance for the application of phase transition devices.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Review
Chemistry, Multidisciplinary
Parker Schofield, Adelaide Bradicich, Rebeca M. Gurrola, Yuwei Zhang, Timothy D. Brown, Matt Pharr, Patrick J. Shamberger, Sarbajit Banerjee
Summary: Future-generation neuromorphic computing aims to emulate the functions of neurons and synapses in the human brain in order to overcome the limitations of current computing architectures. This article discusses VO2 as an attractive material candidate and strategies for tuning its transformation characteristics. The importance of mechanistic understanding and inverse design is emphasized.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sergey Mutilin, Victor Ya Prinz, Lyubov Yakovkina, Anton K. Gutakovskii
Summary: This study developed a strategy for the formation of hybrid Si/VO2 nanostructures compatible with standard silicon technology, based on selective synthesis of VO2 crystals on 3D silicon structures. The method allows for precise arrays of VO2 nanorings on silicon cylinders, opening up possibilities for post-silicon optoelectronics and neuromorphic circuits.
Article
Engineering, Electrical & Electronic
Ozan Gunes, Cyril Koughia, Chunzi Zhang, George Belev, Shi-Jie Wen, Qiaoqin Yang, Safa O. Kasap
Summary: The study investigated self-heating-induced electrical and optical switching in high quality VO2 films grown on a c-cut sapphire substrate, under various constant current pulses. Results showed that the application of constant current pulses caused significant changes in electrical conductivity, optical transmittance, and film temperature, with different temporal behaviors observed depending on the magnitude of the current pulses. The observed phenomena were explained using a simple model based on percolation theory, confirmed by structural insulator-to-metal transition results obtained from Raman micromapping.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Multidisciplinary Sciences
Xitao Guo, Yonghao Tan, Yupei Hu, Zainab Zafar, Jun Liu, Jijun Zou
Summary: The vapor transport method was used to synthesize high quality VO2 thin films on SiO2/Si substrate, exhibiting good near-infrared response and high stability. SEM and Raman spectroscopy were utilized to investigate the morphological and structural evolutions of intermediate phases during nucleation and growth processes, revealing a mechanism dominated by melting-evaporation-nucleation-growth.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Sunbin Deng, Haoming Yu, Tae Joon Park, A. N. M. Nafiul Islam, Sukrit Manna, Alexandre Pofelski, Qi Wang, Yimei Zhu, Subramanian K. R. S. Sankaranarayanan, Abhronil Sengupta, Shriram Ramanathan
Summary: The integration of artificial neurons and synapses on the same substrate using selective area carrier doping has been demonstrated. Nanoscale control over carrier density is achieved by configuring pairs of catalytic and inert electrodes, allowing for appropriate allocation of volatility or nonvolatility to each Mott memory device. The successful integration of both neuron- and synapse-like devices on a single chip enables the realization of feedforward neural motifs and simulation of network-level recognition tasks.
Article
Physics, Applied
Junhao Niu, Qianyu Yao, Wei Mo, Chunhui Li, Tao Chen
Summary: We propose a switchable metamaterial absorber (MMA) based on the phase-transition characteristics of vanadium dioxide (VO2), achieving bandwidth tunable broadband and four-band absorption in the terahertz (THz) band. The MMA demonstrates over 90% broadband absorption in the 3.06-7.61, 3.18-8.91, and 2.78-9.22 THz ranges for different conductivity values of VO2, and it also achieves high absorption at four different frequencies when VO2 is in the insulator phase. The proposed MMA solves the problem of decreased absorption bandwidth caused by a decrease in VO2 conductivity and has potential applications in stealth technology and selective thermal emitters.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Multidisciplinary Sciences
Jan O. Schunck, Florian Doering, Benedikt Roesner, Jens Buck, Robin Y. Engel, Piter S. Miedema, Sanjoy K. Mahatha, Moritz Hoesch, Adrian Petraru, Hermann Kohlstedt, Christian Schuessler-Langeheine, Kai Rossnagel, Christian David, Martin Beye
Summary: This study demonstrates the use of imaging soft X-ray absorption spectroscopy to investigate the insulator-metal transition in vanadium dioxide thin-film microstructures. The experimental results show that the transition temperature for the conversion from insulating to metallic vanadium dioxide is lower near the structure edges compared to the center. The technique provides a detailed understanding of the relationship between the electronic properties of quantum materials and their patterning at the micrometer scale.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Jyrki Lappalainen, Matti Kangaspuoskari
Summary: The metal-insulator transition (MIT) of VO2 has attracted significant attention for its potential applications in nanostructured devices. The dynamics of the MIT phase transition play a crucial role in determining the feasibility of VO2 material properties in various applications. A new model is proposed to accurately predict the MIT effect in VO2 thin films by considering the interface structure and strain energy.
Article
Chemistry, Physical
Yuanyuan Cui, Kebing Yang, Lanli Chen, Bin Liu, Guang Yang, Yanfeng Gao
Summary: By conducting first-principles calculations, this study explored the interface of VO2/TiO2 superlattices, revealing an alternating metal-insulator behavior with an increasing number of VO2 layers.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Wenqiang Xiang, Boris Le Drogoff, Mohamed Chaker
Summary: Depositing high-quality VO2 thin films on a large area has been a challenge. This study presents an improved technique called sputtering oxidation coupling (SOC) using VN as intermediate material. VN films are first deposited on quartz by magnetron sputtering and then annealed in oxygen to obtain VO2 films with good performance in terms of transition properties. The proposed method is comparable to Pulsed Laser Deposition (PLD) in producing high-quality VO2 films.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Da Li, Qilang Wang, Xiangfan Xu
Summary: This study reported the size-dependent thermal conductivity of vanadium dioxide nanowires, revealing that thicker nanowires exhibit higher thermal conductivity and a more significant thermal conductivity jump at the metal-insulator transition temperature. Phonons were identified as the dominant heat carriers in both metallic and insulating regimes, possibly due to the coexistence of metal and insulator phases at high temperatures.
Article
Nanoscience & Nanotechnology
Qiwu Shi, Ke Tian, Hongfu Zhu, Zi-Run Li, Li-Guo Zhu, Hua Deng, Wanxia Huang, Qiang Fu
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Nanoscience & Nanotechnology
Tangdong Feng, Wanxia Huang, Hongfu Zhu, Xueguang Lu, Sujit Das, Qiwu Shi
Summary: This study successfully achieved high-efficiency modulation of THz waves with optical-transparent self-assembled MXene films, transitioning from antireflection to reflection-enhancing. It provides a new pathway for developing MXene films with optical-transparency and smart THz reflection characteristics.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Applied
Zhiyao Yan, Wanxia Huang, Xiongrui Jiang, Junzheng Gao, Yiwen Hu, Hengzhong Zhang, Qiwu Shi
Summary: This study proposed the design of microporous hollow structure in black TiO2 with thickness-controllable nano-shells to optimize its photocatalytic ability, showing excellent light absorption and enhanced photocatalysis performance with decreased shell thickness. The photocatalytic efficiency of the 20-nm shells was about 8 times higher than that of the 145-nm shells, indicating the strong promotion effect of the nano-shell design on the photocatalytic activity of hollow black TiO2.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Physical
Hongfu Zhu, Jiang Li, Xueguang Lu, Qiwu Shi, Lianghui Du, Zhaohui Zhai, Sencheng Zhong, Weijun Wang, Wanxia Huang, Liguo Zhu
Summary: Phase change materials have unique advantages in reconfigurable photonic devices due to their tunable photoelectric properties. This study investigated the thermal equilibrium process and ultrafast dynamics of Ge2Sb2Te5 (GST) driven by femtosecond pulses. The results demonstrated both crystallization and amorphization induced by the pulses, and the threshold for photoinduced crystallization and amorphization was determined. The cumulative photothermal effect was found to play a crucial role in the ultrafast crystallization, and the modulation depth of the volatile and nonvolatile terahertz was limited. Additionally, a distinctive phonon absorption at a specific frequency was observed, providing evidence for crystalline lattice formation. Finally, multistate terahertz switching was achieved by adjusting the optical pump fluence. These findings provide insights into the photoinduced phase change of GST and its potential applications in all optical terahertz functional devices.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Review
Biotechnology & Applied Microbiology
Zhiyao Yan, Li-Guo Zhu, Kun Meng, Wanxia Huang, Qiwu Shi
Summary: In this review, the authors discuss the research progress of Terahertz (THz) medical imaging for in vivo applications. They focus on the development of imaging contrast agents and novel imaging methods suitable for living organisms, and propose a roadmap for taking THz medical imaging from in vitro to in vivo.
TRENDS IN BIOTECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Weibiao Ren, Wanxia Huang, Hongfu Zhu, Daoyuan Wang, Li-Guo Zhu, Qiwu Shi
Summary: This study proposes a method to prepare VO2 thin films on natural mica substrate using RF reactive sputtering, achieving high-performance flexible VO2 films through temperature and thickness optimization. The film exhibits significant resistance change and THz switching ratio, showing potential for flexible oxide electronics applications.
Article
Engineering, Electrical & Electronic
Wei Kou, Wenqiao Shi, Yaxin Zhang, Ziqiang Yang, Ting Chen, Jianqiang Gu, Xilin Zhang, Qiwu Shi, Shixiong Liang, Feng Lan, Hongxin Zeng
Summary: This study presents a tunable focusing planar lens based on a phase gradient vanadium dioxide composite metasurface controlled by an external thermal stimulus. The composite metasurface can show a different phase gradient distribution through the insulator-metal phase transition characteristics of the vanadium dioxide components, enabling switchable focusing.
IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Qiwu Shi, Eric Parsonnet, Xiaoxing Cheng, Natalya Fedorova, Ren-Ci Peng, Abel Fernandez, Alexander Qualls, Xiaoxi Huang, Xue Chang, Hongrui Zhang, David Pesquera, Sujit Das, Dmitri Nikonov, Ian Young, Long-Qing Chen, Lane W. Martin, Yen-Lin Huang, Jorge Iniguez, Ramamoorthy Ramesh
Summary: This study elucidates the fundamental role of lattice dynamics in ferroelectric switching and highlights the importance of a dynamic clamping process occurring during switching.
NATURE COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Hongfu Zhu, Jiang Li, Lianghui Du, Lijun Shan, Peng Li, Xueguang Lu, Tangdong Feng, Sujit Das, Wanxia Huang, Qiwu Shi, Liguo Zhu
Summary: This study proposes a VO2-metallic hybrid metasurface that achieves agile frequency and amplitude modulation for THz waves by depositing high-quality VO2 thin films onto a metasurface. The resonance frequency and amplitude can be tuned dominantly by the change of dielectric constant and conductivity of VO2, enabling precise control of THz transmission. This research provides a new route for developing VO2-based THz smart devices and shows great promise for applications in THz sensor and modulation.
Article
Materials Science, Ceramics
Yuelong Pan, Hao Guo, Xueling Zhang, Zhidong Zhang, Qiwu Shi, Tiecheng Lu
Summary: One of the critical issues in the application of supercritical water oxidation technology is to improve the corrosion resistance of reactor materials. The use of Al2O3 coating is a promising method to address this issue. In this study, thick NiAl/Al2O3 coatings were prepared and their phase structure and coating thickness were studied. The results show that the diffusion of Al and the formation of intermetallic compounds contribute to the corrosion resistance improvement. The thick NiAl/Al2O3 coatings exhibit satisfactory corrosion resistance after supercritical water tests.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Yu Cai, Hongfu Zhu, Jiang Li, Qiwu Shi, Ye Cheng, Lei Chang, Wanxia Huang
Summary: In this study, we investigated the ultrafast terahertz response of Ti2O3 film excited by a femtosecond laser. We observed a transient photoinduced carrier generation process, followed by a fast relaxation and a slow transition process, which can be explained by nonradiative relaxation and photothermal conversion.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Engineering, Chemical
Dengyang Chen, Lisha Zhang, Chengzhe Gao, Qiwu Shi, Silin He, Zhao Wang, Yajie Lei, Guangxian Li, Pengjian Gong
Summary: The urgent need for low-dielectric materials with low THz signal loss in sixth-generation (6G) communication has led to the development of a method to introduce air into the matrix and maintain the stability of the air structure. In this study, low-dielectric poly(tetrafluoroethylene) (PTFE) was used to form nanofibers in polyphenylene sulfide (PPS) to create a nanocomposite with ultralow dielectric air introduced using supercritical CO2 foaming. The resulting PTFE@PPS nanocomposite microcellular foam exhibited excellent low-dielectric properties and hydrophobic performance, making it a promising material for low THz signal loss applications in 6G communication.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Optics
Yiwen Hu, Zhiyao Yan, Lianghui Du, Yongliu Yu, Wanxia Huang, Qiwu Shi
Summary: In this study, black TiO2 hollow shells were prepared using silica spheres as templates, and the combination of gold nanoparticles resulted in yolk-shell structures, which enhanced the visible light absorption and photocatalytic performance.
Article
Nanoscience & Nanotechnology
Zaixin Gan, Feiliang Chen, Qian Li, Mo Li, Jian Zhang, Xueguang Lu, Lu Tang, Zhao Wang, Qiwu Shi, Weili Zhang, Wanxia Huang
Summary: In this paper, a reconfigurable PUF (R-PUF) is proposed and demonstrated using the reversible phase transition behavior of VO2 nanocrystals combined with TiO2 disordered nanoparticles, achieving variable and reproducible optical response. The hysteresis characteristic generated by temperature changes provides a simple way to regulate and control the response behaviors of the R-PUF, improving its security and encoding capacity.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Hongfu Zhu, Jiang Li, Lianghui Du, Wanxia Huang, Jingbo Liu, Jinhao Zhou, Yuanfu Chen, Sujit Das, Qiwu Shi, Liguo Zhu, Cangli Liu
ADVANCED MATERIALS INTERFACES
(2020)
