Article
Physics, Multidisciplinary
Qing-Fen Jiang, Jie Lian, Min-Ju Ying, Ming-Yang Wei, Chen-Lin Wang, Yu Zhang
Summary: The structures, morphologies, and optical properties of Zn-polar ZnO films modified by ion implantation with different concentrations of krypton ions were investigated. The absorption spectrum, photoluminescence, and spectroscopic ellipsometry results showed that krypton ion implantation led to increased absorption, reduced bandgap, and decreased refractive index in the films. This study contributes to the design and optimization of krypton ion-implanted polar ZnO films for optoelectronic applications.
Article
Chemistry, Physical
Prashant Ghediya, Hui Yang, Takashi Fujimoto, Yuqiao Zhang, Yasutaka Matsuo, Yusaku Magari, Hiromichi Ohta
Summary: Amorphous transparent oxide semiconductor InGaZnO4 (IGZO)-based thin-film transistors (TFTs) are widely used as the backplane for flat panel displays. In order to achieve higher-definition displays in the future, alternative active materials with higher field effect mobility (μFE) are needed. In this study, it is shown that a zinc-rich composition enhances the electron transport properties of IGZO(m)-TFTs. The best TFT performance was obtained with m = 7, and the carrier effective mass of IGZO(m) films was found to be 0.16 m(0), independent of the m-value. The present results provide a strategy for improving the design of next-generation TFTs with higher μFE values.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Prashant Ghediya, Hui Yang, Takashi Fujimoto, Yuqiao Zhang, Yasutaka Matsuo, Yusaku Magari, Hiromichi Ohta
Summary: Amorphous transparent oxide semiconductor InGaZnO4 (IGZO)-based thin-film transistors (TFTs) have been practically used in flat panel displays. Alternative active materials with higher field effect mobility (mu(FE)) are necessary for future higher-definition displays. This study shows that a Zn-rich composition enhances the electron transport properties of IGZO(m)-TFTs. The results provide a strategy for improving next-generation TFTs with higher mu(FE) values.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Nanoscience & Nanotechnology
Stanislav Tiagulskyi, Roman Yatskiv, Hana Faitova, Ondrej Cernohorsky, Jan Vanis, Jan Grym
Summary: The experimental approach demonstrated in this study prototypes heterojunctions between graphene and bulk semiconductor substrates using focused ion beam milling and in-situ electrical measurements. The aim is to limit the impact of defects in graphene on the electrical characteristics of the junctions. The approach is successfully applied to graphene/ZnO structures and experimentally validates theoretical predictions of differences in charge transport.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Engineering, Electrical & Electronic
Amalendu Bera, Sourav Chattopadhyay
Summary: A p-Si/Zn(Mg)O/ZnO/Zn(Fe)O heterostructure was fabricated and investigated for light-emitting diode applications. The results showed non-ideal diode behavior at room temperature, with specific spectral peaks and wavelength ranges observed.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Xueqing Hu, Joanna Borowiec, Yijia Zhu, Xiaopeng Liu, Ruiqi Wu, Alex M. Ganose, Ivan P. Parkin, Buddha Deka Boruah
Summary: This study explores the use of zinc oxide nanorods (NRs) and nanoflakes (NFs) as artificial layers on zinc anodes to enhance the performance of zinc-ion batteries (ZIBs). The incorporation of ZnO improves charge storage performance by facilitating efficient electron transport and desolvation of Zn2+ ions. The highly polar surfaces of ZnO NFs promote strong interactions with water molecules, resulting in exceptional hydrophilicity and improved battery performance.
Article
Chemistry, Physical
Pawel Kempisty, Karol Kawka, Akira Kusaba, Yoshihiro Kangawa
Summary: This paper presents an improved theoretical view of ab initio thermodynamics for polar GaN surfaces under gallium-rich conditions. The study uses density functional theory (DFT) calculations to systematically investigate the adsorption of gallium atoms on GaN polar surfaces, starting from the clean surface and progressing to the metallic multilayer. The analysis confirms that a monolayer of Ga adatoms on the GaN(000-1) surface is highly stable over a wide range of temperatures and provides a better thermodynamic description of the surface state under conditions typical for molecular beam epitaxy.
Article
Chemistry, Multidisciplinary
Valentina Cantelli, Sophie Guillemin, Eirini Sarigiannidou, Francesco Carla, Bruno Berini, Jean-Michel Chauveau, Dillon D. Fong, Hubert Renevier, Vincent Consonni
Summary: The polarity of ZnO nanowires affects their nucleation process and morphology development. The study shows that the formation of ZnO nanowires follows three phases and the characteristics of each phase depend on the polarity of the nanowires. This research provides a deeper understanding of the physicochemical processes at work during the growth of ZnO nanowires.
Article
Chemistry, Physical
ChenLin Wang, MinJu Ying, Jie Lian, MingYang Wei, QingFen Jiang, Qian Li, Yu Zhang, Zhen Xu, YueMing Wang
Summary: In this study, O-polar ZnO films were prepared using molecular beam epitaxy and ion implantation was used to introduce Co ions and Sm ions into the films. Various characterization techniques were employed to study the structure, optical, and dielectric properties of the samples. The results showed changes in surface roughness and dielectric properties after ion implantation, indicating potential for application in optoelectronic devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Nilabh Dish, Rakesh Behera, A. Satyaprasad, Abhay Gautam
Summary: This study successfully grows epitaxial Ag, Au, and Cu films on NaCl crystals using a simple approach, and shows a considerable tolerance towards surface misorientation.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Ning Wang, Peng Wang, Fengzhi Wang, Haiping He, Jinyun Huang, Xinhua Pan, Guangming Zhu, Jiangbo Wang, Zhizhen Ye
Summary: This study investigates the growth of ZnO film on a graphene-buffered sapphire substrate using plasma-assisted molecular beam epitaxy (PAMBE). The results show that the crystal quality of ZnO film can be improved by buffering it with double-layer graphene (DLG), leading to the formation of symmetric pits on the film surface. The findings have implications for the development of simplified growth technology for ZnO-based films and devices.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Peng Wang, Xinhua Pan, Ning Wang, Sinan Zheng, Tao Zhang, Yunze Liu, Yao Wang, Fengzhi Wang, Guangmin Zhu, Jiangbo Wang, Zhizhen Ye
Summary: This study presents a simple and feasible method for preparing high-quality flexible ZnO films by growing peelable ZnO films on graphene/ZnO substrates using plasma-assisted molecular beam epitaxy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Sushma Mishra, Ewa Przezdziecka, Wojciech Wozniak, Abinash Adhikari, Rafal Jakiela, Wojciech Paszkowicz, Adrian Sulich, Monika Ozga, Krzysztof Kopalko, Elzbieta Guziewicz
Summary: The study investigates the structural and transport properties of polycrystalline ZnO films deposited by ALD at different growth temperatures. The electrical properties of the films are significantly influenced by the substrate and growth temperature, with changes in crystallite size affecting carrier scattering. ZnO layers on silicon exhibit lower strain and dislocation density compared to those on sapphire, and both annealing and substrate choice impact film characteristics such as hydrogen impurity concentration.
Article
Chemistry, Physical
Luis Henrique de Lima, Wendell Simoes E. Silva, Iago Aedon Silva Prior, Richard Landers, Abner de Siervo
Summary: The (2x2) reconstruction of ZnO(0001) surface was studied using X-ray photoelectron diffraction (XPD). Through comparing XPD measurements with multiple-scattering simulations, it was confirmed that there is a single Zn vacancy per (2x2) surface unit cell and structures with O adatoms are ruled out. The analysis showed an outward relaxation of the topmost Zn layer, which differs from previous density-functional theory (DFT) calculations. Based on DFT, a new stabilizing mechanism of the ZnO surface through surface reconstruction with three hydrogen atoms occupying the Zn vacancies was proposed. The DFT simulation results were in excellent agreement with the XPD findings. The simulations also suggested that the migration of hydrogen atoms from the bulk to the surface may influence the desorption of surface Zn atoms to create vacancies.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Mojtaba Bagherzadeh, Navid Rabiee, Yousef Fatahi, Rassoul Dinarvand
Summary: A Zn-rich (GaN)(1-x)(ZnO)(x) nanostructure was synthesized using a high-gravity technique for drug and gene delivery systems. The nanomaterial exhibited good biocompatibility and was tagged with pCRISPR for co-delivery of drug and gene.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Physics, Applied
Furong Han, Xiaobing Chen, Jianlin Wang, Xudan Huang, Jine Zhang, Jinghua Song, Banggui Liu, Yuansha Chen, Xuedong Bai, Fengxia Hu, Baogen Shen, Jirong Sun
Summary: The research reports on the growth behavior of heterostructures formed on interfaces with symmetry mismatch, specifically focusing on the growth of La2/3Sr1/3MnO3/YBaCo2O5+delta (LSMO/YBCO) on SrTiO3. High-quality crystal structures of LSMO and YBCO were observed without any atomic rearrangement at the interface. Surprisingly, LSMO buffered by YBCO shows perpendicular magnetic anisotropy (PMA) with robust stability, even with a thin YBCO layer. This phenomenon is attributed to orbital reconstruction and the formation of a covalent bond between Mn and Co caged by different oxygen polyhedrons.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Xiang-Bo Xiao, Bang-Gui Liu
Summary: Researchers have discovered three stable freestanding oxide 2D monolayers using first-principles method, which are wide-gap semiconductors with large out-of-plane dipoles. The optical properties of these monolayers have been investigated and compared with graphene and MoS2. These findings are believed to be useful in novel electronic and optoelectronic devices utilizing emerging phenomena in perovskite oxide heterostructures.
Article
Physics, Condensed Matter
Xiaobing Chen, Jine Zhang, Banggui Liu, Fengxia Hu, Baogen Shen, Jirong Sun
Summary: Heterointerfaces between infinite-layer oxide and perovskite oxide exhibit distinct interfacial effects, including the presence of a two-dimensional electron gas (2DEG) that exists in both interface layers. The metallicity of the new interface is robust even as the thickness of the SrCuO2 layer decreases. The conducting states in the interface layer follow the d(xy) form due to the absence of apical oxygen.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
San-Dong Guo, Xiao-Shu Guo, Xiu-Xia Cai, Bang-Gui Liu
Summary: In this study, a model for valley polarization transition at different valley points produced by biaxial strain is proposed, illustrated with a Janus GdClF monolayer. It is found that the strained GdClF monolayer always maintains energy bandgap, strong FM coupling, and PMA within the considered strain range. Compressive strain favors -K valley polarization, while tensile strain favors K valley polarization, with potential applications in multifunctional valleytronic and piezoelectric devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
San-Dong Guo, Wen-Qi Mu, Bang-Gui Liu
Summary: Based on first-principles calculations, it was found that the monolayer RuBr2 can exhibit valley-polarized quantum anomalous Hall insulator (VQAHI) under certain conditions, which holds potential for electronic device applications. The study emphasizes the importance of electronic correlation and perpendicular magnetic anisotropy in investigating ferrovalley materials.
Article
Nanoscience & Nanotechnology
Bo-Wen Yu, Bang-Gui Liu
Summary: The study demonstrates that a stronger ferromagnetic H ' phase can be formed from a VSe2 monolayer by applying uniaxial stress or strain, leading to potential applications in high-performance spintronic and optoelectronic devices.
Article
Chemistry, Physical
San-Dong Guo, Meng-Xia Wang, Yu-Ling Tao, Bang-Gui Liu
Summary: In this work, the Janus monolayer YBrI is demonstrated to be a dynamically, mechanically, and thermally stable piezoelectric ferromagnetic material. The electronic correlation effects and magnetic anisotropy properties of YBrI are investigated, revealing its distinct physical properties. The study also discovers both in-plane and out-of-plane piezoelectricity in YBrI. The findings of these distinctive properties could pave the way for designing multifunctional spintronic devices and constructing 2D materials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
San-Dong Guo, Yu-Ling Tao, Wen-Qi Mu, Bang-Gui Liu
Summary: This study investigates the impact of spin-orbit coupling combined with electronic correlation on the physical properties of monolayer OsBr2. It is found that OsBr2 undergoes threefold topological phase transition with increasing correlation strength and can exhibit valley polarized quantum anomalous Hall insulator to half-valley-metal to ferrovalley insulator transitions. The topological phase transitions are associated with Berry curvature and band inversion between specific orbital states. The piezoelectric properties of OsBr2 are confined along the in-plane direction, and the valley polarization can be manipulated by reversing the magnetization.
FRONTIERS OF PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Wenxiao Shi, Jine Zhang, Xiaobing Chen, Qinghua Zhang, Xiaozhi Zhan, Zhe Li, Jie Zheng, Mengqin Wang, Furong Han, Hui Zhang, Lin Gu, Tao Zhu, Banggui Liu, Yunzhong Chen, Fengxia Hu, Baogen Shen, Yuansha Chen, Jirong Sun
Summary: By modifying the entangled multi-degrees of freedom of transition-metal oxides, the symmetry-mismatch-driven interfacial phase transition from paramagnetic to ferromagnetic state is achieved in this work. The interfacial layer of CaRuO3, with approximately 3 unit cells in thickness, shows robust ferromagnetic order with a high Curie temperature of approximately 120 K and a large saturation magnetization of approximately 0.7 mu(B) per formula unit. Density functional theory calculations reveal that the reduced tilting/rotation of RuO6 octahedra favors an itinerant ferromagnetic ground state. This study demonstrates an effective approach to tune phases by coupled octahedral rotations and offers new opportunities for the exploration of emergent materials with desired functionalities.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Zihao Huang, Guoyu Xian, Xiangbo Xiao, Xianghe Han, Guojian Qian, Chengmin Shen, Haitao Yang, Hui Chen, Banggui Liu, Ziqiang Wang, Hong-Jun Gao
Summary: Landau quantization in a strained type-II Dirac semimetal NiTe2 is studied using spectroscopic-imaging scanning tunneling microscopy. Single-sequence Landau levels originating from the quantization of topological surface state (TSS) are observed on uniform-height surfaces at a magnetic field. Multiple sequence of Landau levels appear in strained surface regions where the rotation symmetry is broken. First-principles calculations reveal that the multiple Landau levels are a result of the lifting of valley degeneracy of TSS by in-plane uniaxial or shear strains. This finding provides a pathway to tune the degrees of freedom and quantum numbers of TMDs for practical applications.
Article
Materials Science, Multidisciplinary
Xiaobing Chen, Jine Zhang, Banggui Liu, Fengxia Hu, Baogen Shen, Jirong Sun
Summary: We report a theoretical investigation on the effects of interface reconstruction on magnetic anisotropy (MA) and Dzyaloshinskii-Moriya interaction (DMI) for nonisostructural heterostructures. We found that the atomic, charge, spin, and orbital reconstructions at the interface allowed for a great tuning of the magnetic anisotropy oscillation behavior. We also observed a strong and tunable DMI, with the minimal value obtained at a specific interface.
Article
Materials Science, Multidisciplinary
San-Dong Guo, Yu-Tong Zhu, Jia-Lin Xin, Bang-Gui Liu
Summary: Through first-principles calculations, it has been found that stable monolayer Fe2Br2 possesses high Chern number and exhibits characteristics of a quantum anomalous Hall insulator. The out-of-plane magnetic anisotropy is crucial for the quantum anomalous Hall state and is robust against biaxial strain. These findings open new possibilities for designing high-temperature topological quantum devices.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
San-Dong Guo, Jing-Xin Zhu, Meng-Yuan Yin, Bang-Gui Liu
Summary: Electronic correlation and magnetic anisotropy play a crucial role in determining the electronic properties of materials. The study shows that increasing electron correlation effects can induce phase transitions, and magnetic anisotropy is strongly dependent on the U value. Different orbital distributions and magnetocrystalline directions also affect the material properties.
Article
Materials Science, Multidisciplinary
San-Dong Guo, Jing-Xin Zhu, Wen-Qi Mu, Bang-Gui Liu
Summary: This study introduces monolayer GdCl2 as a potential material for valleytronic applications, with strong FM coupling and a valley splitting of 42.3 meV. The research also discusses the possible way to achieve the anomalous valley Hall effect in monolayer GdCl2 using the piezoelectric effect.
Article
Chemistry, Physical
San-Dong Guo, Wen-Qi Mu, Xiang-Bo Xiao, Bang-Gui Liu
Summary: The monolayer FeI1-xBrx (x = 0.25 and 0.75) are proven to be stable and excellent room-temperature PQAHIs with high Curie temperatures, sizable gaps and high Chern number. The different crystal phases have significant effects on the out-of-plane piezoelectric response, with the beta phase having a higher piezoelectric strain coefficient.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
