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
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
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, 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.
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
Nanoscience & Nanotechnology
Kun Han, Liang Wu, Yu Cao, Hanyu Wang, Chen Ye, Ke Huang, M. Motapothula, Hongna Xing, Xinghua Li, Dong-Chen Qi, Xiao Li, X. Renshaw Wang
Summary: Enhanced metal-insulator transition (MIT) was achieved in freestanding membranes based on VO2 by inserting an Al2O3 buffer layer, significantly increasing the functionality of ultrathin membranes for potential integration into flexible electronics and photonics applications.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Mohammadreza Farjadian, Majid Shalchian
Summary: A comprehensive model is proposed for describing the insulator to metal phase transition in vanadium dioxide thin film under external electrical stimulus. By dividing the film layer into segments and solving relevant equations, the model successfully replicates experimental results, providing a useful tool for designing and analyzing vanadium dioxide structures with different electrode distances.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
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, Inorganic & Nuclear
Aref Mamakhel, Frederik Holm Gjorup, Magnus Klove, Kasper Borup, Bo Brummerstedt Iversen
Summary: A highly reproducible, simple, and inexpensive synthesis method for obtaining phase-pure thermochromic monoclinic VO2 (M1) is presented. The formation process and transition behavior of VO2 (M1) under heating and cooling conditions were studied using various characterization techniques.
INORGANIC CHEMISTRY
(2022)
Article
Engineering, Electrical & Electronic
Jiahua Qi, Dongping Zhang, Qicong He, Lanxuan Zeng, Yi Liu, Zhuangbing Wang, Aihua Zhong, Xingmin Cai, Fan Ye, Ping Fan
Summary: This study successfully reduces the sheet resistance of VO2 and eliminates its electrical phase change characteristics by inserting a conductive ITO buffer layer. The optical modulation ability remains high, while achieving a low threshold working voltage for electro-optic switches. This result is significant for the practical application of VO2-based optical switches.
SENSORS AND ACTUATORS A-PHYSICAL
(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)
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
Chemistry, Multidisciplinary
Yoon Jung Lee, Kootak Hong, Kyeongho Na, Jiwoong Yang, Tae Hyung Lee, Byungsoo Kim, Chung Wung Bark, Jae Young Kim, Sung Hyuk Park, Sanghan Lee, Ho Won Jang
Summary: By controlling phase transitions in correlated materials, new functional properties can be achieved. This study demonstrates the control of a nonvolatile metal-insulator transition in vanadium dioxide (VO2) using a ferroelectric layer, showing enhanced coupling between correlated electrons and ferroelectric polarization. The research provides insights into interface properties, structural phase transitions, and design principles for heteroepitaxial correlated materials.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Vivek Mootheri, Goutham Arutchelvan, Sreetama Banerjee, Surajit Sutar, Alessandra Leonhardt, Marie-Emmanuelle Boulon, Cedric Huyghebaert, Michel Houssa, Inge Asselberghs, Iuliana Radu, Marc Heyns, Dennis Lin
Summary: This study presents a novel approach of transferring metal-graphene hybrid contacts onto chemical vapor deposition (CVD) MoS2 for 2D FET fabrication, achieving lithography free contacting strategy. The results show that Ru-Gr contact exhibits the lowest contact resistance among the three metal-graphene contact stacks reported, and it also performs the best among CVD grown graphene contacted MoS2 devices. The technique of metal-graphene contact stack transfer represents a technologically relevant approach that can be scaled up for larger wafer areas.
Article
Nanoscience & Nanotechnology
Vivek Mootheri, Alessandra Leonhardt, Devin Verreck, Inge Asselberghs, Cedric Huyghebaert, Stefan de Gendt, Iuliana Radu, Dennis Lin, Marc Heyns
Summary: 2D materials such as MoS2 show promise for further scaling of CMOS technology, but achieving ambipolar transport in MoS2 FETs is challenging due to Fermi level pinning (FLP). This study successfully increases hole transport in MoS2 FETs by adjusting contact and substrate interfaces, demonstrating the material's ambipolar nature. The results highlight the importance of dielectric environment and processing conditions on ambipolar transport in MoS2 FETs.
Article
Physics, Applied
Gianluca Gubbiotti, Alexandr Sadovnikov, Evgeny Beginin, Sergey Nikitov, Danny Wan, Anshul Gupta, Shreya Kundu, Giacomo Talmelli, Robert Carpenter, Inge Asselberghs, Iuliana P. Radu, Christoph Adelmann, Florin Ciubotaru
Summary: This research investigates the characteristics of spin waves in vertical meander-shaped Co40Fe40B20 thin films using Brillouin-light-scattering spectroscopy. The study reveals the presence of frequency band gaps at specific wave numbers, which can be controlled by changing the geometrical parameters of the film.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Applied
Giacomo Talmelli, Daniele Narducci, Frederic Vanderveken, Marc Heyns, Fernanda Irrera, Inge Asselberghs, Iuliana P. Radu, Christoph Adelmann, Florin Ciubotaru
Summary: Spin wave modes in magnetic waveguides with width down to 320nm were studied using electrical propagating spin-wave spectroscopy and micromagnetic simulations under both longitudinal and transverse magnetic bias fields. The results showed a 1.3GHz wide spin-wave band for longitudinal bias fields, while transverse bias fields led to several distinct bands corresponding to different quantized width modes. Micromagnetic simulations revealed nonuniform and tilted magnetization in this geometry, resulting in spin wave dispersion relations in good agreement with experimental observations.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
G. Gubbiotti, A. Sadovnikov, E. Beginin, S. Sheshukova, S. Nikitov, G. Talmelli, I. Asselberghs, I. P. Radu, C. Adelmann, F. Ciubotaru
Summary: In this study, the spin-wave propagation in three-dimensional nanoscale CoFeB/Ta/NiFe meander structures was investigated, revealing the magnonic band structure with a set of stationary modes interposed by dispersive modes. The influence of dipolar coupling between the ferromagnetic layers on the magnonic band structure was compared with single-layer CoFeB meander structures with the same geometry parameters.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
R. A. Izmailov, B. J. O'Sullivan, M. Popovici, J. A. Kittl, V. V. Afanas'ev
Summary: The study suggests using low temperature charge injection and thermally activated emission as a universal method for characterization of shallow traps in high permittivity insulating oxides. The volume concentration of these traps in all studied materials is found to be in the range of 1019-1020 cm-3, indicating that shallow trapping will significantly impact the performance of devices operating at low temperature and/or very short pulse times.
SOLID-STATE ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Jakob Michl, Alexander Grill, Dominic Waldhoer, Wolfgang Goes, Ben Kaczer, Dimitri Linten, Bertrand Parvais, Bogdan Govoreanu, Iuliana Radu, Tibor Grasser, Michael Waltl
Summary: Through experimental results and a quantum mechanical model, we found that at low temperatures, the BTI of pMOSFETs is mainly affected by the SiO2 layer, while the BTI of nMOSFETs is mainly affected by the HfO2 layer, and defects in the HfO2 layer do not freeze out at low temperatures.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Jakob Michl, Alexander Grill, Dominic Waldhoer, Wolfgang Goes, Ben Kaczer, Dimitri Linten, Bertrand Parvais, Bogdan Govoreanu, Iuliana Radu, Michael Waltl, Tibor Grasser
Summary: The study discusses the effectiveness of using the WKB approximation method to simulate charge trapping behavior at low temperatures. It was found that this approximation method can provide excellent results and can be used to model charge trapping behavior at low temperatures.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
K-H Kao, C. Godfrin, A. Elsayed, R. Li, E. Simoen, A. Grill, S. Kubicek, I. P. Radu, B. Govoreanu
Summary: This study investigates the quality of four different gate stacks for cryogenic MOS devices by analyzing the oxide trap density, transconductance, Hall mobility, and critical density. The results provide valuable insights into the material physics at cryogenic temperatures.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Tom Schram, Surajit Sutar, Iuliana Radu, Inge Asselberghs
Summary: This article introduces the applications of large-area 2D-material-based devices in sensor or photonics devices and the back end of line (BEOL), and discusses the requirements, development status, and gaps to be bridged for the full wafer integration of aggressively scaled 2D-based logic circuits.
ADVANCED MATERIALS
(2022)
