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, Multidisciplinary
Tiffany C. Kaspar, Peter Hatton, Kayla H. Yano, Sandra D. Taylor, Steven R. Spurgeon, Blas P. Uberuaga, Daniel K. Schreiber
Summary: Thin film deposition from the vapor phase involves complex adatom adsorption, movement, and incorporation into the growing film. This study provides experimental and simulation evidence for anion intermixing during the deposition process. The research reveals that adatoms on the film surface pull up subsurface oxygen and iron and facilitate their mixing through ring-like rotation mechanisms. These findings contribute to the understanding of thin film deposition and other surface-mediated processes.
Article
Nanoscience & Nanotechnology
Joseph Roth, Tatiana Kuznetsova, Leixin Miao, Alexej Pogrebnyakov, Nasim Alem, Roman Engel-Herbert
Summary: Exotic material properties and topological nontrivial surface states are theoretically predicted to emerge in [111]-oriented perovskite layers. However, the growth of perovskite oxide films along this crystallographic direction has been proven to be difficult due to the highly polar character of the perovskite (111) surface. Successful epitaxial growth of high-quality SrVO3(111) thin films was achieved by hybrid molecular beam epitaxy, opening up opportunities for studying transport properties of topological nontrivial and correlated electron systems.
Article
Chemistry, Multidisciplinary
Ghada Badawy, Bomin Zhang, Tomas Rauch, Jamo Momand, Sebastian Koelling, Jason Jung, Sasa Gazibegovic, Oussama Moutanabbir, Bart J. Kooi, Silvana Botti, Marcel A. Verheijen, Sergey M. Frolov, Erik P. A. M. Bakkers
Summary: The combination of II-VI CdTe with III-V InSb in the form of core-shell nanowires shows potential applications for surface passivation or as tunnel barriers in superconductors. The lattice-matched CdTe can be epitaxially grown on InSb nanowires without introducing interfacial strain or defects.
Article
Chemistry, Multidisciplinary
Xiaotao Xu, Xi He, Anthony T. Bollinger, Xiaoyan Shi, Ivan Bozovic
Summary: A new family of metastable materials, La2-xSrxZnO4 (LSZO), was synthesized by atomic-layer-by-layer molecular beam epitaxy (ALL-MBE), which can form epitaxial materials with a high-temperature superconductor (HTS) compound, La2-xSrxCuO4 (LSCO). By growing La2ZnO4 (LZO) at very low temperatures to form the insulating layer, the superconducting properties of the LSCO electrodes in LSCO/LZO/LSCO trilayers remain undiminished, opening prospects for producing high-quality HTS tunnel junctions.
Article
Crystallography
Allison Boley, Esperanza Luna, C. Zhang, N. Faleev, C. B. Honsberg, David J. Smith
Summary: Studies on epitaxial GaP/Si heterostructures grown by MBE and MEE using ACSTEM revealed significant interfacial intermixing and a wide interface width, which will impact theoretical predictions of charge imbalance and strong electric fields across the heterointerface.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Materials Science, Multidisciplinary
M. A. Zambrano-Serrano, Carlos A. Hernandez, O. de Melo, M. Behar, S. Gallardo-Hernandez, Y. L. Casallas-Moreno, A. Ponce, A. Hernandez-Robles, D. Bahena-Uribe, C. M. Yee-Rendon, M. Lopez-Lopez
Summary: n-GaN/AlN heterostructures were grown on Si(111) substrates by molecular beam epitaxy. The effect of silicon doping concentration on the structural and optical properties was studied. It was found that silicon doping could reduce the dislocation density and the yellow band, and induce a specific mosaic structure. However, there was a slight degradation in crystal quality for heavily doped samples.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Crystallography
Nidhi Gupta, Madhav Ranganathan
Summary: The morphology of self-assembled quantum dots in Ge/Si heteroepitaxial systems is influenced by the intermixing of silicon and germanium. Simulations demonstrate that intermixing reduces strain and slows down the formation of quantum dots. Composition maps provide clear evidence of the relationship between strain and intermixing.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Optics
M. Stachowicz, J. M. Sajkowski, A. Wierzbicka, E. Przezdziecka, M. A. Pietrzyk, E. Dynowska, S. Magalhaes, E. Alves, A. Kozanecki
Summary: The study described the optical properties of homoepitaxially grown ZnO/MgO superlattices on a-oriented ZnO substrates and found that the wurtzite coordination collapses in the SLs with 3 nm MgO thick barriers. The high energy barrier of MgO in such structures allows treating the ZnO layers as separate quantum wells.
JOURNAL OF LUMINESCENCE
(2021)
Article
Chemistry, Multidisciplinary
Lu Han, Xinrui Yang, Yingzhuo Lun, Yue Guan, Futao Huang, Shuhao Wang, Jiangfeng Yang, Chenyi Gu, Zheng-Bin Gu, Lisha Liu, Yaojin Wang, Peng Wang, Jiawang Hong, Xiaoqing Pan, Yuefeng Nie
Summary: Tuning the domain structure of ferroelectric membranes through a combination of elastic and electrostatic engineering provides a new strategy for enhancing and manipulating piezoelectricity. By adjusting the ferroelectric domains from c-dominated to c/a and a structures in freestanding PbTiO3 membranes, the piezoelectric coefficient is significantly enhanced by a factor of 2.5 compared to typical c domain structures. This work demonstrates the great potential of ferroelectric membranes in applications such as nano actuators, transducers, sensors, and other NEMS devices.
Article
Chemistry, Multidisciplinary
Rahmat Hadi Saputro, Ryo Matsumura, Naoki Fukata
Summary: This study reveals the mechanism of dopant redistribution in Sb-doped Ge epitaxial films grown by molecular beam epitaxy, providing insights into the behavior of substituted Sb atoms in forming n-type Ge films. The understanding of these processes opens up possibilities for achieving n(+)-Ge thin films for Ge-based devices with improved electrical properties.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Chemistry, Multidisciplinary
Paulina Ciechanowicz, Sandeep Gorantla, Monika Welna, Agnieszka Pieni, Jaroslaw Serafinczuk, Bogdan Kowalski, Robert Kudrawiec, Detlef Hommel
Summary: Self-induced dodecagonal GaN microrods can be grown by molecular beam epitaxy in Ga-rich conditions due to the antisurfactant properties of arsenic atoms. The investigation of temperature's role in the growth of GaN microrods reveals an optimal growth temperature window of 760-800 degrees C. Lowering the temperature increases the population of irregular and amorphous microrods, while increasing the temperature disrupts the growth of GaN microrods. The incorporation of As in GaN microrods is negligible, as confirmed by X-ray diffraction and transmission electron microscopy.
Article
Materials Science, Multidisciplinary
Chen Shang, Jennifer Selvidge, Eamonn Hughes, Justin C. Norman, Aidan A. Taylor, Arthur C. Gossard, Kunal Mukherjee, John E. Bowers
Summary: With recent developments in high-speed and high-power electronics and Si-based photonic integration, monolithic III-V/Si integration through epitaxial methods is gaining momentum. A novel asymmetric step-graded filter structure grown by molecular beam epitaxy (MBE) has been proposed to reduce threading dislocation density (TDD) for high-quality GaAs on Si growth, providing a clear pathway to further reduce defect density down to theoretical limit.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Maria Gabriela Sales, Shelby Fields, Samantha Jaszewski, Sean Smith, Takanori Mimura, Wendy L. Sarney, Sina Najmaei, Jon F. Ihlefeld, Stephen McDonnell
Summary: Direct integration of transition metal dichalcogenides on a ferroelectric HZO substrate using molecular beam epitaxy (MBE) is investigated in this study. The results show that the crystallinity and composition of the HZO substrate can affect the degree of Se incorporation. However, measurements of the electrical properties of the HZO films did not show any negative impact of the incorporated Se on the functionality of the ferroelectric layer.
Article
Chemistry, Multidisciplinary
Babak Nikoobakht, Aaron C. Johnston-Peck, David Laleyan, Ping Wang, Zetian Mi
Summary: A novel approach was presented for growth of surface-directed spinel ZnGa2O4 and beta-Ga2O3 nanofins coated with a non-polar GaN shell, utilizing a vacancy-assisted mechanism for exchange between Zn and Ga. The predictability over surface registries and tunable porosity of the core/shell fins is anticipated to be significant for various applications.
Article
Chemistry, Analytical
Kelly McHugh, Dushyant Barpaga, Michael Sinnwell, Steve Shen, Vaithiyalingam Shutthanandan
Summary: This work explores the use of metal-organic frameworks (MOFs) as ion emitters for thermal ionization mass spectrometry (TIMS). MOFs show promise in enhancing ionization efficiency and surpassing traditional loading techniques. The experiment with aluminum-based MOF-253 demonstrates the potential of MOFs to enhance ionization and exceed the performance of traditional loading techniques.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Ning Wang, Chen Shen, Zhehao Sun, Haiyan Xiao, Hongbin Zhang, Zongyou Yin, Liang Qiao
Summary: This study investigates the thermal and electrical transport properties of 2D Bi2TeSe2 material using first-principles calculations. The results show that the Bi2TeSe2 monolayer has a low lattice thermal conductivity and enhanced Seebeck coefficient, resulting in a high power factor and optimal ZT value. The findings provide new insights for the application of bismuth-based materials in the high-temperature thermoelectric field.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Ning Wang, Chen Shen, Zhehao Sun, Bingke Li, Haiyan Xiao, Xiaotao Zu, Hongbin Zhang, Zongyou Yin, Liang Qiao
Summary: This study investigates the electronic, mechanical, and thermal properties of layered LaCuOX compounds. The results show that these compounds are mechanically stable and have good ductility and ionic-covalent bonding. Moreover, the thermal conductivity of these compounds varies with the change of the elements.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Venkateshkumar Prabhakaran, Garvit Agarwal, Jason D. Howard, Sungun Wi, Vaithiyalingam Shutthanandan, Dan-Thien Nguyen, Luke Soule, Grant E. Johnson, Yi-Sheng Liu, Feipeng Yang, Xuefei Feng, Jinghua Guo, Kie Hankins, Larry A. Curtiss, Karl T. Mueller, Rajeev S. Assary, Vijayakumar Murugesan
Summary: Charge transfer across the electrode-electrolyte interface is studied using ion soft landing method to prepare well-defined interfaces with molecular precision. In situ multimodal spectroscopic characterization is used to investigate the reactivity of solvated species in Mg batteries. Computed reaction pathways and energy barriers are used to confirm the experimental results. The TFSI reactivity is evaluated under electrochemical conditions using phase-separated electrolytes.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Navid Attarzadeh, Debabrata Das, Srija N. Chintalapalle, Susheng Tan, V. Shutthanandan, C. V. Ramana
Summary: In this study, a highly efficient heterostructure catalyst for hydrogen production was designed using a 3D nano architecture inspired by the prickly pear cactus. The catalyst exhibited superior catalytic activity and stability compared to conventional catalysts. The introduction of heterointerfaces and epitaxial NiS nanosheets expanded the active catalytic surface area and enhanced the intrinsic catalytic activity.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Zhenni Yang, Xiangyu Xu, Yan Wang, Siliang Kuang, Duanyang Chen, Hongji Qi, K. H. L. Zhang
Summary: Si-doped beta-Ga2O3 thin films grown on vicinal a-Al2O3 (0001) substrates exhibit high electrical conductivity and deep ultraviolet (DUV) transparency, making them promising candidates for transparent electrodes. The use of miscut Al2O3 substrates promotes improved crystal quality and electrical properties. The Si-doped films achieved a high conductivity of 37 S cm(-1) and average DUV transparency of 85% on a 6 degrees miscut substrate. The films also exhibit low work function, making them suitable for efficient electron injection in DUV optoelectronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Henry W. Sprueill, Jenna A. Bilbrey, Qin Pang, Peter V. Sushko
Summary: Neural network potentials (NNPs) can accelerate atomistic simulations and allow broader sampling of structural outcomes and transformation pathways. In this study, an active sampling algorithm is demonstrated to train an accurate NNP for microstructural evolutions. The NNP is then used with a perturbation scheme to stochastically sample structural and energetic changes caused by shear-induced deformation, revealing a range of possible intermixing and vacancy migration pathways. The code for the active learning strategy and NNP-driven shear simulations is openly available.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Minghang Li, Wencheng Chen, Jiasheng Zhang, Shuming Bai, Jiarong Zeng, Xueliang Zhu, Kelvin H. L. Zhang, Qijin Cheng, Kostya (Ken) Ostrikov
Summary: AlN is commonly used as a buffer layer in GaN-based LEDs, but when applied on patterned sapphire substrate (PSS), it leads to undesired screw dislocations in the epitaxial layer of GaN. This study demonstrates the use of sputtered AlON buffer layer on industry-grade four-inch PSS to improve the quality of GaN epitaxial layers and enhance the performance of GaN-based blue LEDs. The addition of oxygen to AlN reduces the density of screw dislocations, providing insights into the growth mechanisms and guiding the development of next-generation optoelectronic technologies.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Guangdong Liu, Yang He, Zhixiao Liu, Hui Wan, Yaobin Xu, Huiqiu Deng, Hui Yang, Ji-Guang Zhang, Peter V. V. Sushko, Fei Gao, Chongmin Wang, Yingge Du
Summary: By using in situ transmission electron microscopy and density functional theory calculations, the influence of planar defects on the diffusion pathways and transport kinetics of Li ions in a tungsten trioxide lattice is revealed. It is found that planar defects disrupt the continuity of ion conduction channels by altering the charge distribution and lattice spacing, leading to a significant increase in energy barrier for Li diffusion. This atomic-level understanding has important implications for rational interface design in solid-state batteries and solid oxide fuel cells.
Article
Multidisciplinary Sciences
Fang Li, Xiaoyang Yue, Yulong Liao, Liang Qiao, Kangle Lv, Quanjun Xiang
Summary: In this work, the authors demonstrate the interfacial electron-transfer mechanism in a crystalline triazine/heptazine carbon nitride homojunction. They use surface bimetallic cocatalysts as sensitive probes and conduct in situ photoemission to trace the S-scheme transfer of interfacial photogenerated electrons. The experimental and theoretical results reveal the dynamic nature of the charge transfer and its potential for enhancing CO2 photoreduction.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Matthew Chrysler, Judith Gabel, Tien-Lin Lee, Zihua Zhu, Tiffany C. Kaspar, Mark Bowden, Peter V. Sushko, Scott A. Chambers, Joseph H. Ngai
Summary: Charge redistribution across heterojunctions influences the functionality of materials systems. The composition of the terminating surface affects charge transfer across a Si/SrTiO3 heterojunction. Surface depletion in Si causes itinerant electrons to migrate across the interface and modify the interfacial dipole. This leads to a change in band alignment, which can be weakened by capping the SrTiO3 surface.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yan Sun, Cheng-Rong Wu, Tian-Yi Ding, Jian Gu, Jia-Wei Yan, Jun Cheng, Kelvin H. L. Zhang
Summary: Researchers used electrochemical-scanning tunnelling microscopy (EC-STM) to directly observe the structural dynamics of LaNiO3 (LNO) surface during the oxygen-evolution reaction (OER). They discovered that the reconstruction of surface morphology originated from the transition of Ni species on the LNO surface. The change in surface topography was induced by the Ni(OH)(2)/NiOOH redox transformation. These findings demonstrate the importance of in situ characterization for understanding the dynamic nature of catalyst interfaces and designing efficient electrocatalysts.
Review
Energy & Fuels
Fazli Wahid, Sajjad Ali, Pir Muhammad Ismail, Fazal Raziq, Sharafat Ali, Jiabao Yi, Liang Qiao
Summary: With the increase in energy crisis and greenhouse effect, the development of efficient solar-driven photocatalytic systems for fuels/chemicals production is crucial. Single atom photocatalytic (SAP) systems, consisting of isolated single atoms (SAs) coordinated with a suitable support, have shown superior catalytic efficiency. This review discusses SAPs and the confining of metal SAs on 2D supports, highlighting recent advances, challenges, and future perspectives, aiming to provide ideas for the discovery of novel photocatalytic systems.
PROGRESS IN ENERGY
(2023)
Article
Multidisciplinary Sciences
Prescott E. Evans, Yang Wang, Peter V. Sushko, Zdenek Dohnalek
Summary: This study investigates the deposition of palladium (Pd) on WTe2(001) and finds that Pd nucleation is driven by the interaction with excess tellurium (Te) atoms. The formation of Pd-Te clusters is not affected by surface defects and remains stable at elevated temperatures. These findings are important for the manufacturing of novel quantum and microelectronics devices and catalytically active nano-alloy centers.
Article
Physics, Applied
Hyung-Seok Lim, Sujong Chae, Litao Yan, Guosheng Li, Ruozhu Feng, Yongsoon Shin, Zimin Nie, Bhuvaneswari Modachur Sivakumar, Xin Zhang, Yangang Liang, David Jonathan Bazak, Vaithiyalingam Shutthanandan, Vijayakumar Murugesan, Soowhan Kim, Wei Wang
Summary: This paper presents a new gel polymer interface (GPI) for preventing crossover of vanadium ions in a vanadium redox flow battery, thus improving its cycling stability.
ENERGY MATERIAL ADVANCES
(2022)
