Article
Materials Science, Multidisciplinary
M. Y. Chernykh, A. A. Andreev, I. S. Ezubchenko, I. A. Chernykh, I. O. Mayboroda, E. M. Kolobkova, J. Grishchenko, P. A. Perminov, V. S. Sedov, A. K. Martyanov, A. S. Altakhov, M. S. Komlenok, V. P. Pashinin, A. G. Sinogeykin, V. Konov, M. L. Zanaveskin
Summary: A new approach to fabricating efficient heat sinks for GaN-based transistors is demonstrated, which involves growing a polycrystalline diamond coating on the functional silicon layer of SOI wafers and etching a thick silicon substrate and thin thermal oxide. The heat sink, consisting of a thin monocrystalline silicon layer on top of a thick polycrystalline diamond layer, shows improved heat removal performance compared to conventional technologies. This new substrate fabrication technology has a positive impact on GaN-based device output characteristics and reliability, benefiting communication systems, radars, and secondary power supply systems.
APPLIED MATERIALS TODAY
(2022)
Article
Physics, Applied
Abdul Mannan, Kota Yamahara, Filchito Renee G. Bagsican, Kazunori Serita, Hironaru Murakami, Iwao Kawayama, Masataka Higashiwaki, Masayoshi Tonouchi
Summary: This study investigates the band bending profile of gallium-nitride-based heterostructures with respect to the change in the direction of the induced current, which is detected by laser THz emission microscopy. The research observes different THz emission characteristics in FET and HEMT structures, providing valuable insights into carrier transport and band bending in complex heterostructures.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Kavita T. Upadhyay, Manju K. Chattopadhyay
Summary: This paper provides a review of significant research work in the field of GaN-based sensor technologies, including classification of existing work, explanation of sensor sensing mechanisms, as well as the challenges and future opportunities facing current sensing systems.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2021)
Review
Materials Science, Multidisciplinary
Valentin Jmerik, Alexey Toropov, Valery Davydov, Sergey Ivanov
Summary: This review focuses on the recent progress in the development of monolayer-thick GaN/AlN multilayer heterostructures for deep-ultraviolet optoelectronics. The advantages of different epitaxial methods and characterization techniques are compared, while the optical properties of ML-thick GaN/AlN quantum wells and their potential in UVC emitter applications are investigated.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Chenguang Zhang, Wenliang Wang, Xiaodong Hao, Yong Peng, Yulin Zheng, Jia Liu, Yiyuan Kang, Fujian Zhao, Zhengtang Luo, Junjie Guo, Bingshe Xu, Longquan Shao, Guoqiang Li
Summary: This study utilized GaN/AlGaN materials with controlled polarity to induce endogenous electrical stimulation for bone regeneration, finding that Ga-polarity GaN/AlGaN nanofilms showed superior bone repair in vivo and promoted osteogenic differentiation of bone mesenchymal stem cells in vitro. Additionally, the study revealed that bone morphogenetic protein-6 (BMP6) may be an electrically sensitive osteogenic protein.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Computer Science, Interdisciplinary Applications
Massimo Salvi, Francesco Branciforti, Federica Veronese, Elisa Zavattaro, Vanessa Tarantino, Paola Savoia, Kristen M. Meiburger
Summary: Dermatological images are typically diagnosed based on visual analysis of skin lesions acquired using a dermoscope. However, the quality of the acquired image can be affected by variations in illumination conditions, which can decrease the accuracy of diagnosis. In this study, a novel Dermatological Color Constancy Generative Adversarial Network (DermoCC-GAN) algorithm is proposed to overcome the limitations of existing algorithms by formulating color constancy as an image-to-image translation problem.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2022)
Article
Engineering, Electrical & Electronic
Vanjari Sai Charan, Sandeep Vura, R. Muralidharan, Srinivasan Raghavan, Digbijoy N. Nath
Summary: A novel Sc/Al/Ni/Au metal scheme was developed for Ohmic contacts to InAIN/GaN HEMT structures on silicon, achieving a contact resistance of 0.39 Omega-mm and low surface roughness after annealing. Microstructural analysis revealed the formation of ScGaN inclusions in the GaN channel layer and a non-uniform layer of ScInAIN on top of the InAIN barrier, with field-emission as the dominant conduction mechanism. Polarization mismatch due to structural modifications was suggested as the possible mechanism related to Ohmic contact formation.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Automation & Control Systems
Zhe Zhang, Jiasheng Huang, Yudi Xiao
Summary: This article proposes a partial parallel dual active bridge (PPDAB) converter combined with Gallium Nitride (GaN) transistors in order to reduce the current stress over the switching devices on the low-voltage side. By integrating three transformers and their associated interfacing inductors, a more compact design is achieved. Additionally, a new method of utilizing leakage inductance as the interfacing inductor is introduced to improve efficiency and power density.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Chemistry, Physical
Lalrinkima, Lalthakimi Zadeng, Lalmuan Chhana, Lalhriat Zuala, D. P. Rai
Summary: In this study, the surface stability and surface half-metallicity of Ti2XSi (X=Mn/Co) [001] slab were investigated using first principles calculation. The results showed that the TiSi(Ti2MnSi) terminated surface is the most stable and exhibits surface half-metallicity with 100% spin polarization within the allowed chemical potentials range.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
A. Ezaier, R. Masrour, M. Hamedoun, J. Kharbach, A. Rezzouk, A. Hourmatallah, N. Benzakour, K. Bouslykhane
Summary: In this study, the structural, electronic, magnetic, thermodynamic, optical, and thermoelectric properties of Nd (Co1-xFex)2 compounds were investigated using density functional theory (DFT) with the Generalized Gradient Approximation (GGA) and GGA + U methods. The results showed that the Nd(Co0.5 Fe0.5)2 alloy had a total magnetic moment of 17.73 mu B/f.u. according to the GGA method and 18.21 mu B/f.u. with the GGA + U method. The effects of temperature on thermal properties were studied using the quasi-harmonic Debye model. The compound Nd(Co0.25 Fe0.75)2 exhibited significant optical properties such as a static refractive index of n(0) = 28.0 and an optical conductivity of 10431 (omega.cm)-1.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Chemistry, Physical
Lanli Chen, Hongduo Hu, Chao Kang, Aiping Wang, Zhihua Xiong, Yuanyuan Cui, Yanfeng Gao
Summary: The electronic structures and magnetic properties of ZnO/GaN lateral heterostructures (LHSs) are investigated systematically through first-principles calculations. It is found that the width and strain engineering, as well as vacancy defects, influence their properties significantly. Different types of band transitions, semiconducting-to-metallic conversions, and band alignments are observed with varying width and strain. Vacancy defects can modulate the magnetic properties of the LHSs, with different types of defects leading to different magnetic moments. This study provides important guidance for understanding and controlling the electronic properties of ZnO/GaN LHSs, and expands the potential applications in nano-optoelectronics devices.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Physical
Qing Liu, Yu Qing Yang, Xingfu Wang, Weidong Song, Xingjun Luo, Jiaqi Guo, Jiang Shi, Chuan Cheng, Dongyang Li, Longfei He, Kai Li, Fangliang Gao, Shuti Li
Summary: The study demonstrates a hybrid heterostructure photodetector combining GaN microwire array and perovskite, showing superior photoelectric performance in a wide detection range from ultraviolet to visible light. This is attributed to effective separation of photogenerated carriers at the hetero-interface and directional transfer of carriers within the GaN microwire array, shedding light on fabricating high-performance heterostructure photodetectors.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Haoran Li, Zhibin Yang
Summary: Mid-infrared (MIR) photodetection is crucial in modern technologies like biomedical devices and free-space communication. 2D materials and heterostructures have been widely used in MIR photodetectors due to their tunable bandgaps and strong light absorption. This review summarizes the recent progress of MIR photodetectors based on van der Waals (vdWs) heterostructures.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Physical
Eui Young Choi, Seok Hyeon Hong, Byeong Kook Park, Prahallad Padhan, Wilfrid Prellier, Seung Young Park, Younghun Jo, Byeong Cheol Min, Ji Won Seo
Summary: A systematic study on electrically controlled magnetization in tri-layers of ferromagnetic SrRuO3 and antiferromagnetic insulating manganites reveals that interface-driven magnetic inhomogeneity can act as a bridge between current and magnetism, leading to new functionalities in heterostructures.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Lina G. Johnsen, Sol H. Jacobsen, Jacob Linder
Summary: A compensated antiferromagnetic interface can influence the adjacent superconducting phase transition by controlling magnetization, despite the system being invariant under rotations of magnetization without the antiferromagnetic layer. Additionally, the superconducting phase transition can trigger a reorientation of the ground state magnetization.
Article
Chemistry, Physical
Fernando Valadares, Ivan Gudhon, Lara K. Teles, Marcelo Marques
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Physics, Condensed Matter
Filipe Matusalem, Marcelo Marques, Ivan Guilhon, Lara K. Teles
JOURNAL OF PHYSICS-CONDENSED MATTER
(2020)
Article
Chemistry, Physical
Fernando Valadares, Ivan Guilhon, Lara K. Teles, Marcelo Marques
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Construction & Building Technology
G. F. da Silva, S. Martini, J. C. B. Moraes, L. K. Teles
Summary: This study analyzed the electrical properties of cement mortar with graphene oxide (GO) and nanofibrillated cellulose (NFC) using an equivalent impedance circuit. The results showed that the addition of nanomaterials affected the electrical resistance of the high-frequency arc and matrix porosity, which in turn influenced compressive strength. The findings suggest that impedance spectroscopy is a useful tool for monitoring the curing process and microstructure evolution of cementitious composites with nanoreinforcements.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Physics, Condensed Matter
Filipe Matusalem, Friedhelm Bechstedt, Ivan Guilhon, Marcelo Marques, Lara K. Teles
Summary: A computationally efficient methodology for calculating Z(2) topological invariants is presented and applied to group-IV graphene-like systems, showing the importance of quasiparticle (QP) effects in predicting the topological or trivial character.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
Ronaldo Rodrigues Pela, Claudia Draxl
Summary: Linearized augmented planewaves combined with local-orbitals (LAPW + lo) are a precise basis set for representing Kohn-Sham states, especially when used in real-time time-dependent density functional theory (RT-TDDFT). This work presents an implementation of RT-TDDFT in the full-potential LAPW + lo code, which shows satisfactory agreement with benchmark results from other codes. Three examples are provided to illustrate possible applications of this implementation: dynamic excitations in MoS2 induced by a laser pulse, third harmonic generation in silicon, and a pump-probe experiment in diamond. Additional benchmark results are also provided.
ELECTRONIC STRUCTURE
(2021)
Article
Chemistry, Physical
Fernando Valadares, Ivan Guilhon, Lara K. Teles, Marcelo Marques
Summary: The study highlights the potential of CsSnGeI3 alloy as a non-toxic, stable, and high-performance compound for photovoltaic applications. Theoretical analysis reveals its basic properties and structural transition tendencies.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Physics, Condensed Matter
Lucas Yagui, Ivan Guilhon, Marcelo Marques, Lara K. Teles
Summary: This study evaluates the performance of a low computational cost ab initio DFT-1/2 method in transition metal oxide perovskites. The results demonstrate the remarkable accuracy of this method for these materials, providing possibilities for studying more complex systems.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Chemistry, Physical
Ronaldo Rodrigues Pela, Claudia Draxl
Summary: This paper presents the implementation of Ehrenfest dynamics combined with real-time time-dependent density functional theory for studying non-adiabatic molecular dynamics. It allows for real-time assessment of electronic excitations generated by ultra-fast laser pulses and their coupling to nuclear vibrations. The implementation in the all-electron full-potential package exciting is demonstrated through examples of diamond and cubic boron nitride, with good agreement found when compared with the Octopus code.
ELECTRONIC STRUCTURE
(2022)
Article
Chemistry, Physical
Clovis Caetano, Ivan Guilhon, Giancarlo Cappellini, Marcelo Marques, Lara K. Teles
Summary: Quaternary halide double perovskites have a range of electronic properties and can be used in various optoelectronic applications. However, determining their band gap has been challenging with discrepancies in reported results. In this study, we use first-principles methods to investigate the electronic structure of cesium chloride double perovskites, and employ the DFT-1/2 approximate quasiparticle method to accurately determine the band gap. This approach offers a computationally efficient alternative for studying complex systems.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Condensed Matter
Tulio Mota, Filipe Matusalem, Marcelo Marques, Lara K. Teles, Ivan Guilhon
Summary: This paper presents the results and methodology of applying the DFT-1/2 method to five three-dimensional topological insulator materials. It shows that the DFT-1/2 method provides accurate results for band gaps, band shapes, atomic character, and topological invariants, making it a useful tool for studying the topological properties of materials.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)