Article
Physics, Applied
Saadia Nasir, Zhengtianye Wang, Sivakumar Mambakkam, Stephanie Law
Summary: This paper investigates in-plane DPP coupling in TI stripe arrays and finds that the coupling becomes negligible when the lattice constant is greater than approximately 2.8 times the stripe width. This understanding could be crucial for the development of TI-based metasurfaces.
APPLIED PHYSICS LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Mithun Ghosh, P. D. Babu, P. S. Anil Kumar
Summary: In this study, the longitudinal resistivity, anisotropic magnetoresistance (MR), and Hall effect of epitaxial Nd2Ir2O7 (111) thin films were investigated. The results showed that the magnetic structure of Ir4+ 5d moments could be tuned by applying a magnetic field along different crystallographic directions. A large spontaneous Hall effect (SHE) signal and a topological-like Hall signal were observed, indicating the presence of Weyl semimetallic phase and multiple Weyl nodes in the electronic band structure of the films.
Article
Multidisciplinary Sciences
Sudhanshu Gautam, V Aggarwal, Bheem Singh, V. P. S. Awana, Ramakrishnan Ganesan, S. S. Kushvaha
Summary: In this study, Bi2Se3 thin films of different thicknesses were grown on sapphire substrates using radio frequency magnetron sputtering technique. The physical properties and conduction mechanism of the films were characterized using various techniques. The results showed that the films exhibited metallic nature and gapless topological surface states at low temperatures, and a positive magneto-resistance effect in magnetic fields. The conduction mechanism varied with the thickness of the films.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Yogesh Kumar, Prince Sharma, V. P. S. Awana
Summary: In this study, bismuth selenide thin films of varying thicknesses were deposited on a SiO2 substrate. The films were characterized and their transport properties were investigated, revealing the thickness dependence of weak anti-localization effect in Bi2Se3/SiO2 thin films.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Physics, Applied
C. Barone, P. Orgiani, G. Carapella, V. Granata, S. K. Chaluvadi, S. Pagano
Summary: Topological insulators like Bi2Se3 have unique properties due to their distinct surface band structure. A study on low-frequency noise spectroscopy in Bi2Se3 thin films reveals a reduction in the 1/f noise component, especially at low temperatures. The correlation between this behavior and structural and dc electric transport investigations suggests the possibility of the occurrence of the topological regime. Flicker noise measurements could provide an alternative technique for studying topological surface states.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
E. Rogacheva, O. Pavlosiuk, A. Meriuts, T. N. Shelest, A. Yu Sipatov, O. N. Nashchekina, K. Novak, D. Kaczorowski
Summary: The transport coefficients of polycrystalline Bi2Se3 films, grown on glass substrates, were studied as a function of temperature and magnetic field. The study revealed the presence of weak antilocalization effect at weak magnetic fields, but also a transport paradox characterized by a logarithmic increase in longitudinal resistance with decreasing temperature. Additionally, kinks in the temperature dependence of the Hall resistance, Hall coefficient, and magnetoresistance were observed near a certain temperature. The results indicate that quantum interference effects and transport paradox can be observed not only in very thin monocrystalline films, but also in polycrystalline Bi2Se3 films of significant thickness prepared by thermal evaporation.
Article
Materials Science, Multidisciplinary
Na Li, Yun-bin Sun, Rui Sun, Xu Yang, Wei Zhang, Zong-kai Xie, Jia-nan Liu, Yan Li, Yang Li, Zi-zhao Gong, Xiang-qun Zhang, Wei He, Zhao-hua Cheng
Summary: Topological insulators with distinct topological surface states have been widely investigated for spintronics and quantum information devices. This study reveals that the topological surface states can significantly accelerate ultrafast demagnetization and enhance the damping factor of heterostructures. These findings have implications for future topological spintronic devices or quantum information processing.
Article
Nanoscience & Nanotechnology
Hak Dong Cho, Juwon Lee, Deuk Young Kim, Sung Yun Chung, Jong-Kwon Lee
Summary: High-quality Bi2Se3 thin films with topological insulating properties are grown on a patterned sapphire substrate (PSS), showing enhanced light absorption and high crystallinity. The fabricated IR conversion device using Bi2Se3/PSS heterostructure exhibits excellent performance and high reliability. The enhanced device performance of Bi2Se3/PSS is confirmed by increased absorption spectra and improved light absorption distribution.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Multidisciplinary Sciences
Zengguang Cheng, Tara Milne, Patrick Salter, Judy S. Kim, Samuel Humphrey, Martin Booth, Harish Bhaskaran
Summary: The research demonstrates the potential of using nanometer-scale metals to enhance light-matter interactions, with antimony as a pure metal capable of optically programmable transitions between two states. Its application prospects lie in optoelectronic modulation and switching speed, showcasing the simplicity and potential for various optoelectronic applications requiring actively tunable metallic conductors.
Article
Engineering, Electrical & Electronic
Valerio Campanari, Daniele Catone, Patrick O'Keeffe, Alessandra Paladini, Stefano Turchini, Faustino Martelli, Matteo Salvato, Nouha Loudhaief, Elena Campagna, Paola Castrucci
Summary: Carrier dynamics in polycrystalline Bi2Se3 topological insulator thin films were studied using femtosecond transient absorption spectroscopy. The observed absorption bleaching signals can be attributed to electronic transitions involving both bulk and surface states in the complex Bi2Se3 band structure. The differences in rise times of the bleaching signals provide insights into the band filling dynamics and the efficient population of surface topological states by carrier-phonon scattering.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jui-Chi Chung, Aswin Kumar Anbalagan, Chen-Lin Fan, Yu-Hao Liao, Akhil K. Ramesh, Shivam Gupta, Yuan-Chieh Tseng, Nyan-Hwa Tai, Chih-Hao Lee
Summary: This study investigates the magnetic phase transition temperature of FeRh thin films and demonstrates that doping copper impurities can significantly reduce the transition temperature. The decrease in temperature is attributed to a reduction in long-range order of AFM and other factors such as lattice strain and valence electrons per atom.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Shanquan Chen, Shuai Yuan, Zhipeng Hou, Yunlong Tang, Jinping Zhang, Tao Wang, Kang Li, Weiwei Zhao, Xingjun Liu, Lang Chen, Lane W. Martin, Zuhuang Chen
Summary: The paper explores recent advances in the study of topological spin/polarization structures in ferroic materials, including the evolution of topological spin structures and exotic polar topologies in magnetic thin films and ferroelectric oxide films. It discusses the control of these structures and emergent phenomena through factors such as epitaxial strain, layer thickness, electric fields, and magnetic fields. Additionally, the paper provides a brief overview and prospectus for the future development of the field in the coming years.
ADVANCED MATERIALS
(2021)
Article
Physics, Applied
Molly P. Andersen, Linsey K. Rodenbach, Ilan T. Rosen, Stanley C. Lin, Lei Pan, Peng Zhang, Lixuan Tai, Kang L. Wang, Marc A. Kastner, David Goldhaber-Gordon
Summary: Nanostructured topological insulators (TIs), such as the Bi2Se3 family, have great potential in various areas of condensed matter physics. However, the commonly used electron beam lithography with higher accelerating voltages (30 or 50 kV) causes unacceptable damage to both nonmagnetic TIs and their magnetically doped counterparts. This study demonstrates that using a lower accelerating voltage (10 kV) significantly reduces the damage without compromising the ability to create fine features.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
K. Kronfeldner, T. Baturina, C. Strunk
Summary: This study measured the magnetoresistance of a TiN thin film close to the disorder-driven superconductor-insulator transition, identifying three distinct crossing points in magnetic fields at different temperatures. The evolution of these crossing points near the transition was systematically studied, with estimates provided for the critical exponents z and nu.
Review
Chemistry, Multidisciplinary
Ruben Gracia-Abad, Soraya Sangiao, Chiara Bigi, Sandeep Kumar Chaluvadi, Pasquale Orgiani, Jose Maria De Teresa
Summary: Bi2Se3, a topological insulator with a simple surface band structure and a relatively large band gap, has garnered attention for its potential in transport properties. Studies have revealed a significant relationship between the mobility and phase coherence length in Bi2Se3 thin films, indicating potential for further experiments on transport in topological systems.
Article
Physics, Applied
Hosik Lee, Jino Im, Hosub Jin
APPLIED PHYSICS LETTERS
(2020)
Article
Multidisciplinary Sciences
Jungmin Park, Inseon Oh, Mi-Jin Jin, Junhyeon Jo, Daeseong Choe, Hyung Duk Yun, Suk Woo Lee, Zonghoon Lee, Soon-Yong Kwon, Hosub Jin, Suk Bum Chung, Jung-Woo Yoo
SCIENTIFIC REPORTS
(2020)
Article
Chemistry, Multidisciplinary
Chongjian Zhou, Yuan Yu, Yea-Lee Lee, Bangzhi Ge, Weiqun Lu, Oana Cojocaru-Miredin, Jino Im, Sung-Pyo Cho, Matthias Wuttig, Zhongqi Shi, In Chung
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Physical
Myeongjeong Lee, Byeongjun Yoo, Jino Im, Taeghwan Hyeon, In Chung
ACS APPLIED ENERGY MATERIALS
(2020)
Article
Energy & Fuels
Byung-wook Park, Hyoung Woo Kwon, Yonghui Lee, Do Yoon Lee, Min Gyu Kim, Geonhwa Kim, Ki-jeong Kim, Young Ki Kim, Jino Im, Tae Joo Shin, Sang Il Seok
Summary: The study shows that using isopropylammonium to stabilize the perovskite structure greatly improves the long-term stability of solar cells, leading to enhanced efficiency performance.
Article
Chemistry, Physical
Chongjian Zhou, Yong Kyu Lee, Yuan Yu, Sejin Byun, Zhong-Zhen Luo, Hyungseok Lee, Bangzhi Ge, Yea-Lee Lee, Xinqi Chen, Ji Yeong Lee, Oana Cojocaru-Miredin, Hyunju Chang, Jino Im, Sung-Pyo Cho, Matthias Wuttig, Vinayak P. Dravid, Mercouri G. Kanatzidis, In Chung
Summary: The research found that by controlling the purity of tin reagents and removing tin oxide impurities, the thermal conductivity of SnSe polycrystalline samples can be reduced, resulting in excellent performance with ZT of 3.1 at 783 K.
Article
Chemistry, Physical
Sae Jin Sung, Jino Im, Geunjin Kim, Chan Su Moon, Jason J. Yoo, Seong Sik Shin, Nam Joong Jeon, Boo Soo Ma, Dong Jun Kim, Taek-Soo Kim, Jangwon Seo
Summary: By introducing the interface modifier CEPA, the interface of perovskite solar cells can be optimized, achieving defect passivation, improving energy level alignment, enhancing interfacial adhesion energy and mechanical stability, thus improving the efficiency and long-term stability of solar cells.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Yea-Lee Lee, Hyungseok Lee, Taeshik Kim, Sejin Byun, Yong Kyu Lee, Seunghun Jang, In Chung, Hyunju Chang, Jino Im
Summary: The research presents a data-driven method to optimize and improve the thermoelectric performance of doped SnSe compounds, rapidly screening high-dimensional material spaces using machine learning predictive models and calculated maps.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Jino Im, Choong H. Kim, Hosub Jin
Summary: This study reveals that polar lattice distortion can directly couple to the Berry curvature (BC) dipole of phonons, leading to a switchable nonlinear phonon Hall effect. They observed the phononic version of the BC memory effect and the phonon Rashba effect in a SnS monolayer, where in-plane ferroelectricity induces a phonon BC and opens a mass gap in tilted Weyl phonon modes. Furthermore, their ab initio non-equilibrium molecular dynamics simulations demonstrate controllable nonlinear phonon Hall transport via ferroelectric switching.
Article
Chemistry, Multidisciplinary
Young Yun Kim, Su-Mi Bang, Jino Im, Geunjin Kim, Jason J. Yoo, Eun Young Park, Seulki Song, Nam Joong Jeon, Jangwon Seo
Summary: To achieve mass production of perovskite solar modules, it is important to develop large-area fabrication methods for high-quality perovskite films with eco-friendly solvents. This study successfully develops an eco-friendly solvent/co-solvent system for producing high-quality perovskite films with a large-area antisolvent bathing method. The resulting perovskite solar modules show high efficiency and long-term stability. The new solvent system based on MSM is also effective in low-temperature or high-humidity environments.
Article
Nanoscience & Nanotechnology
Yea-Lee Lee, Hyungseok Lee, Seunghun Jang, Jeongho Shin, Taeshik Kim, Sejin Byun, In Chung, Jino Im, Hyunju Chang
Summary: TEXplorer is a web-based platform designed to collect and share all types of thermoelectric materials data, provide valuable tools for data processing and visualization, and predict thermoelectric properties through machine learning models. This study used TEXplorer to collect and manage the thermoelectric dataset of SnSe and Bi2Te3 with various doping/alloying elements, aiming to explore the complex relationship between these elements and the thermoelectric properties of the host materials. The web-based interactive data platform enables efficient management and utilization of experimental and computational datasets, supporting the acceleration of data-driven materials research and autonomous material synthesis.
Article
Chemistry, Physical
Jin Wook Yoo, Eunseo Noh, Jihun Jang, Kyoung Su Lee, Junseop Byeon, Mansoo Choi, Jino Im, Sang Il Seok
Summary: The higher thermodynamic stability of formamidinium lead triiodide (FAPbI3) in the yellow non-perovskite (8-phase) compared to the black perovskite (a-phase) at room temperature leads to spontaneous transition from the a-phase to the 8-phase. However, band gap broadening and halide segregation limit the stabilization of a-FAPbI3 through alloying the perovskite composition. In this study, the a-phase of FAPbI3 was stabilized without band gap broadening using R4N+ cations and Cl- anions. This led to the fabrication of high-efficiency perovskite solar mini-modules (PSMs) with a maximum power conversion efficiency (PCE) of 20.33% (certified 21.23%, 36.4-cm2 area). The encapsulated PSM retained 93% of its initial PCE after 870 hours under continuous one-sun illumination.
Article
Materials Science, Multidisciplinary
Kyoung-Whan Kim, Hogyun Jeong, Jeongwoo Kim, Hosub Jin
Summary: Research on modifying the definition of Berry curvature to explain vertical Hall effects and in-plane transport phenomena has important implications for quantum transport on two-dimensional platforms.
Article
Physics, Multidisciplinary
Seunghee Lee, Hyun Woo Kim, Jino Im, Seok Ki Kim, Yong Tae Kim, Hyunju Chang, Tae-Wook Ko, Jonggul Lee, YunKyong Hyon
JOURNAL OF THE KOREAN PHYSICAL SOCIETY
(2020)