Article
Chemistry, Physical
Jie Mao, Zhenao Gu, Yue Yu, Huijuan Liu, Jiuhui Qu, Xiaoqiang An
Summary: This study integrated visual observation techniques and material synthesis strategies to reveal the structure-activity relationship of a single BiVO4 photocatalyst, confirming the significance of facet engineering for enhancing photocatalytic activity.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Yuuki Adachi, Yasuhiro Sugawara, Yan Jun Li
Summary: Probing CO on a rutile TiO2(110) surface using atomic force microscopy and Kelvin probe force microscopy enables the resolution of the interatomic dipole moment and charge state of CO at atomic resolution. The results suggest that both charge state and on-surface dipole interaction play a significant role in the reaction of CO on rutile TiO2(110) surface.
Article
Chemistry, Multidisciplinary
Emilie Gachon, Patrick Mesquida
Summary: Collagen fibrils exhibit a surface charge dependency on longitudinal strain, becoming more positive within 10% strain and more negative between 10% to 17% strain. This change is correlated with fibril stiffness and may be influenced by structural rearrangements. Kelvin-probe force microscopy testing on fibrils attached to an extensible, thin polymer film allows for the determination of electrical surface potential.
Article
Chemistry, Multidisciplinary
Devon S. Jakob, Nengxu Li, Huanping Zhou, Xiaoji G. Xu
Summary: This article introduces a novel method to generate Coulombic force in KPFM, increasing the spatial resolution to approximately 25 nm. By integrating PiFM, high spatial resolution chemical distributions and surface potential maps can be obtained concurrently. This is expected to facilitate characterizations of nanoscale electrical properties of photoactive materials, semiconductors, and ferroelectric materials.
Article
Chemistry, Multidisciplinary
Haijie Ben, Yong Liu, Xiao Liu, Xiufan Liu, Cancan Ling, Chuan Liang, Lizhi Zhang
Summary: Constructing a PDI/BiOI heterojunction with diffusion-controlled charge separation process through elaborately fabricated methods, the research reveals the effectiveness of diffusion-controlled driving force in enhancing photocatalytic activities. The study sheds light on the importance of diffusion-controlled charge separation and offers useful insights for the design of high-performance heterojunction photocatalysts for practical applications.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Energy & Fuels
Christian Kameni Boumenou, Amala Elizabeth, Finn Babbe, Alice Debot, Harry Moeenig, Alex Redinger
Summary: The study investigated the buried MoSe2/CuInSe2 interface of stoichiometric absorbers in thin film solar cells, revealing differences in local density of states compared to the front-side properties. This sheds new light on the complex interface formation in CuInSe2-based thin film solar cells grown under Cu-rich conditions.
PROGRESS IN PHOTOVOLTAICS
(2021)
Article
Chemistry, Physical
Mario Navarro-Rodriguez, Elisa Palacios-Lidon, Andres M. Somoza
Summary: The ability to retain localized charges at the surface or interface of dielectric materials is a universal property that has applications in various fields. In this study, equations are derived to model the decay of localized charge distributions, and a useful tool for determining material conductivities is proposed. Experimental verification of the predicted behavior is conducted.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Mengkang Xu, Xinpeng Tian, Qian Deng, Qun Li, Shengping Shen
Summary: By introducing nanocracks and applying continuously varying mechanical loading, the evolution of flexoelectricity around the crack tips in SrTiO3, Ba0.67Sr0.33TiO3, and TiO2 samples has been successfully measured. This method provides a reliable way to identify the significance of the flexoelectric effect and may open a new avenue for the study of flexoelectricity involving multiple physics phenomena such as flexoelectronics and the flexo-photovoltaic effect.
Article
Chemistry, Multidisciplinary
Shangzhi Gu, Wenyu Liu, Shuo Mi, Guoyu Xian, Jiangfeng Guo, Fei Pang, Shanshan Chen, Haitao Yang, Hong-Jun Gao, Zhihai Cheng
Summary: In this study, the twist angle-dependent work functions of twisted bilayer graphene (tBLG) were investigated using Kelvin probe force microscopy (KPFM) and Raman spectroscopy. The surface potentials of Bernal-stacked multilayer graphene were measured to determine the relationship between twist angle and surface potential. It was found that the work function of tBLG decreases and tends to saturate with increasing number of layers. Controlled annealing process showed that tBLG transforms into Bernal-stacked bilayer graphene. This research provides valuable insights into the twist angle-dependent surface potentials and electronic properties of tBLG.
Article
Chemistry, Physical
Hwi Je Woo, Seongchan Kim, Young-Jin Choi, Jeong Ho Cho, Seong Heon Kim, Young Jae Song
Summary: The work function of graphene devices on SiO2 substrates is studied using Kelvin probe force microscopy, revealing gate voltage-dependent work-function hysteresis. The inhomogeneous distribution of chemical species at the graphene/SiO2 interface leads to varying degrees of hysteresis across different positions on the graphene.
Article
Nanoscience & Nanotechnology
Ryo Izumi, Masato Miyazaki, Yan Jun Li, Yasuhiro Sugawara
Summary: The recently proposed high-low Kelvin probe force microscopy (KPFM) allows for the evaluation of semiconductor interface states with high spatial resolution using high and low AC bias frequencies. This is important for assessing the energy spectrum of interface state density in semiconductor devices. In this study, a method called high-low Kelvin probe force spectroscopy (high-low KPFS) is proposed, which measures the interface state density inside semiconductors using high and low-frequency AC bias voltages. Preliminary experiments on ion-implanted silicon surfaces confirmed the dependence of electrostatic force on AC bias voltage frequency and obtained the interface state density.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Jill Serron, Albert Minj, Valentina Spampinato, Alexis Franquet, Yevhenii Rybalchenko, Marie-Emmanuelle Boulon, Steven Brems, Henry Medina Silva, Yuanyuan Shi, Benjamin Groven, Renan Villarreal, Thierry Conard, Paul van der Heide, Thomas Hantschel
Summary: This study investigates the rapid intercalation of water vapor at the interface of transition metal dichalcogenides (TMDs) and sapphire, as well as between two TMD monolayers, and examines its impact on their electrical properties. The findings reveal that water vapor can intercalate rapidly within a few minutes and show partial reversibility under (ultra)-high vacuum conditions. Complete desorption of intercalated water clusters significantly enhances the electronic properties of TMDs, but also indicates that the characterization of TMD samples is significantly affected by the presence of water intercalation in air, inert environments, and even vacuum. Moreover, the study highlights a correlation between water intercalation and the presence of defects, contributing to the gradual degradation of TMDs as they age.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Woongbin Yim, Van Tu Nguyen, Quynh Thi Phung, Hwan Sik Kim, Yeong Hwan Ahn, Soonil Lee, Ji-Yong Park
Summary: The spatial distribution of photogenerated carriers in atomically thin MoS2 flakes and their correlation with photocurrent generation is investigated using Kelvin probe force microscopy. The study reveals that surface potential changes can image the vertical redistribution of photogenerated carriers, and the trapping of photogenerated holes at the interface between MoS2 and the substrate is the main mechanism for the photoresponse.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Energy & Fuels
C-S Jiang, D. Albin, M. Nardone, K. J. Howard, A. Danielson, A. Munshi, T. Shimpi, C. Xiao, H. R. Moutinho, M. M. Al-Jassim, G. Teeter, W. Sampath
Summary: This paper investigates the stability and electric field distribution of CdTe devices with a structure of TCO/MZO/CdSeTe/CdTe/backcontact. The results show reversible transitions between the light-soak state (LSS) and the dark-soak state (DSS), but irreversible degradation occurs after long-hour light soaking at an elevated temperature. The electric field profiles at different states reveal the presence of a buried homojunction (BHJ) in the LSS and an increased electric field near the MZO/CdSeTe interface at the DgS.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Chemistry, Multidisciplinary
Priscilla F. Pieters, Antoine Laine, He Li, Yi-Hsien Lu, Yashpal Singh, Lin-Wang Wang, Yi Liu, Ting Xu, A. Paul Alivisatos, Miquel Salmeron
Summary: This study reveals the nanoscale origin and important characteristics of enhanced dielectric breakdown capabilities in gold nanoparticle/polymer nanocomposites. The improved breakdown strength is related to the interfacial charge retention capability at the nanoscale. At the meso- and macroscales, the concentration and distribution of nanoparticles play a crucial role in determining and enhancing the dielectric properties.
Article
Chemistry, Physical
Xiaojun Qiao, Wenping Geng, Yao Sun, Dongwan Zheng, Yun Yang, Jianwei Meng, Jian He, Kaixi Bi, Min Cui, Xiujian Chou
Summary: This study prepared epitaxial BiFeO3 thin films using PLD technology, and characterized their morphology, local polarization state, and piezoelectric response by SPM and PFM. The research observed robust in-plane domain dynamic processes and good retention and repeatability under high temperatures. The newly developed domain patterns are nearly stable, possibly influenced by built-in electric fields and tip field distributions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Hongli Wang, Kaiyang Zeng
Summary: This study investigated the evolution of domain structures of [001]-oriented relaxor ferroelectric 0.93PbZn(1/3)Nb(2/3)O(3)-0.07PbTiO(3) (PZN-7%PT) single crystals as a function of temperature using piezoresponse force microscopy (PFM). The results showed that the temperature-dependent domain structures undergo a phase transition process from rhombohedral to monoclinic, tetragonal, and finally cubic phases as the temperature increases. This direct observation of phase transition evolution is significant for understanding the relationships between the domain structure and phase structure of PZN-7%PT single crystals.
Article
Chemistry, Multidisciplinary
Qibin Zeng, Hongli Wang, Zhuang Xiong, Qicheng Huang, Wanheng Lu, Kuan Sun, Zhen Fan, Kaiyang Zeng
Summary: The traditional PFM technique faces challenges and limitations in its validity and applications, leading to the development of an advanced HM-PFM technique. HM-PFM utilizes high-frequency excitation and heterodyne method to accurately measure piezoelectric strain at the nanoscale, providing standard domain and hysteresis loop measurements. Notably, HM-PFM can effectively minimize contributions from electrostatic force and electrochemical strain, making it a promising tool for ferroelectric or piezoelectric studies.
Article
Engineering, Biomedical
Zhichao Ma, Zhenfeng Qiang, Kaiyang Zeng, Jianlin Xiao, Liming Zhou, Lihui Zu, Hongwei Zhao, Luquan Ren
Summary: The study utilized depth-sensing nanoindentation to obtain hardness distribution map of cortical bones, and successfully predicted the fracture path under compressive stress by analyzing the correlation between hardness distribution map and compressive fracture path. The feasibility of the prediction method was verified through experiments, and the relation between the fracture propagation path and distribution of Haversian canals was also analyzed.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Article
Chemistry, Physical
Hongli Wang, Kaiyang Zeng
Summary: The study showed that the increase in relative humidity leads to an increase in PFM amplitude and a decrease in coercive bias of ferroelectric hysteresis loops. These phenomena are attributed to the presence of a water layer between the probe tip and the sample surface, which affects the electric field distribution and screening properties at the ferroelectric sample surface.
Article
Nanoscience & Nanotechnology
Qiaomei Sun, Jin An Sam Oh, Li Lu, Kaiyang Zeng
Summary: The surface features of solid electrolytes play a crucial role in determining their physical properties and their interaction with electrode materials. This study focuses on regulating the surface chemistry of solid electrolytes through thermal treatments and analyzing their interaction with metallic anodes using scanning probe microscopy techniques at the nanoscale.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Applied
Qibin Zeng, Kaiyang Zeng
Summary: Using a mechanical pump scheme, oscillation dynamics in a single commercial microcantilever resonator can be parametrically controlled, enabling phonon-cavity coupling, parametric amplification, and parametric cooling. By utilizing a mechanical pump, the sensitivity and signal-to-noise ratio of frequency-modulated Kelvin probe force microscopy operated in ambient conditions can be significantly improved, while also allowing for the creation of thermomechanical noise-squeezing states in the microcantilever.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Jin An Sam Oh, Jianguo Sun, Minhao Goh, Bengwah Chua, Kaiyang Zeng, Li Lu
Summary: All-solid-state alkaline metal batteries are considered ideal high energy density storage systems, but require stable physical contact between the anode and solid-state electrolyte. By using a composite anode and enhancing Na+ diffusion kinetics, the tendency to form pores during desodiation can be reduced, leading to stable cycling.
ADVANCED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Shuai Chang, Yu Zhang, Bangmin Zhang, Xun Cao, Lei Zhang, Xiaolei Huang, Wanheng Lu, Chun Yee Aaron Ong, Shuang Yuan, Chaojiang Li, Yizhong Huang, Kaiyang Zeng, Liqun Li, Wentao Yan, Jun Ding
Summary: The development of a highly active and conductive Shellular electrode for efficient oxygen evolution reaction (OER) in large-scale hydrogen production through water electrolysis is achieved by embedding nanocrystalline Ni3Nb intermetallics. The designed structure has a large surface area and high porosity, achieving a record-high current density at a record-low overpotential with good durability, potentially opening the door for large-scale industrial water electrolysis.
ADVANCED ENERGY MATERIALS
(2021)
Article
Physics, Applied
Yue Liu, Kailin Ren, Kaiyang Zeng
Summary: This article discusses the complexity of the contact resonance frequency (f(0)) signal in piezoresponse force spectroscopy, as well as the physical significance and influencing factors of this signal variation, and proposes directions for improving relevant models and mechanisms.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Jin An Sam Oh, Yumei Wang, Qibin Zeng, Jianguo Sun, Qiaomei Sun, Minhao Goh, Bengwah Chua, Kaiyang Zeng, Li Lu
Summary: This study introduces a simple and cost-effective annealing process to improve the interface between the electrolyte and metallic sodium. The annealed electrolyte shows an extremely small interfacial resistance and high critical current density, providing insight into electrolyte surface preparation and its significance in a sodium-metal solid-state battery.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Chemistry, Physical
Jianguo Sun, Hualin Ye, Jin An Sam Oh, Yao Sun, Anna Plewa, Yumei Wang, Tian Wu, Kaiyang Zeng, Li Lu
Summary: Introducing nickel hexacyanoferrate (NNiFCN) onto the outer layer of iron hexacyanoferrate (NFFCN) through ion exchange improves structural stability and enhances the kinetics of sodium ion diffusion. As a result, the electrochemical performance is significantly improved with a remarkable long-term cycling stability, making NNiFCN/NFFCN core-shell structured cathode a promising candidate for full sodium-ion batteries in large-scale energy storage applications.
Article
Chemistry, Applied
Jianguo Sun, Yao Sun, Jin An Sam Oh, Qilin Gu, Weidong Zheng, Minhao Goh, Kaiyang Zeng, Yuan Cheng, Li Lu
Summary: Nitrogen-doped carbon micro-rods with enlarged inter-layer spacing are synthesized for application as anodes in sodium-ion batteries, exhibiting stable capacity and high cyclability due to improved sodium ion intercalation and electric conductivity.
JOURNAL OF ENERGY CHEMISTRY
(2021)
Article
Chemistry, Physical
Jianguo Sun, Hualin Ye, Jin An Sam Oh, Anna Plewa, Yao Sun, Tian Wu, Qiaomei Sun, Kaiyang Zeng, Li Lu
Summary: The study highlights the advantages of iron hexa-cyanoferrate in terms of ion diffusion kinetics, reducing the activation energy barrier of low-spin Fe and inducing intercalation pseudocapacitance. The high-spin Fe and low-spin Fe redox reactions exhibit ion diffusion behavior and pseudocapacitance behavior respectively. Manipulating the Fe redox kinetics through inducing special coordinated groups can potentially lead to the design of high-voltage SIBs with improved cycling stability and rate performance.
ENERGY STORAGE MATERIALS
(2021)
Article
Chemistry, Physical
Qibin Zeng, Qicheng Huang, Hongli Wang, Caiwen Li, Zhen Fan, Deyang Chen, Yuan Cheng, Kaiyang Zeng
Summary: The study introduces a high-resolution non-contact measurement technique, NC-HEsFM, for nanoscale ferroelectric characterization, offering better performance compared to traditional PFM. By utilizing a QTF sensor, multi-frequency operation, and heterodyne detection schemes, NC-HEsFM achieves true non-contact yet non-destructive ferroelectric characterization, while providing ideal conditions for investigating ferroelectric phenomena.
