Quantitative 3D-KPFM imaging with simultaneous electrostatic force and force gradient detection

Kelvin probe force microscopy (KPFM) is a powerful characterization technique for imaging local electrochemical and electrostatic potential distributions and has been applied across a broad range of materials and devices. Proper interpretation of the local KPFM data can be complicated, however, by convolution of the true surface potential under the tip with additional contributions due to long range capacitive coupling between the probe (e.g. cantilever, cone, tip apex) and the sample under test. In this work, band excitation (BE)-KPFM is used to negate such effects. In contrast to traditional single frequency KPFM, multifrequency BE-KPFM is shown to afford dual sensitivity to both the electrostatic force and the force gradient detection, analogous to simultaneous amplitude modulated and frequency modulated KPFM imaging. BE-KPFM is demonstrated on a Pt/Au/SiO x test structure and electrostatic force gradient detection is found to lead to an improved lateral resol...

L Collins, M B Okatan, Q Li, I I Kravenchenko, N V Lavrik, S V Kalinin, B J Rodriguez and S Jesse

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Low-temperature liquid phase reduced TiO 2 nanotube arrays: synergy of morphology manipulation and oxygen vacancy doping for enhancement of field emission

The partially reduced TiO 2 nanotube arrays (TNAs) are prepared via an uncomplicated and low-cost liquid phase reduction strategy using NaBH 4 as the reducing agent. By controlling and adjusting the reduction temperatures from 30 to 90 °C, the reduction treatment can not only change their surface morphology but also introduce oxygen vacancies into them, resulting in an optimized morphology, elevated Fermi-level, reduced effective work function and improved conductivity of the TNAs. Meanwhile, the thermal and long-term stability of oxygen vacancy are also investigated, indicating that the oxygen vacancies retain long-term stability from room temperature up to 150 °C. More interesting, partially reduced TNAs show drastically enhanced field emission (FE) performances including substantially decreased turn-on field from 18.86 to 1.53 V μ m −1 , a high current density of 4.00 mA cm −2 at 4.52 V μ m −1 , and an excellent FE st...

Xu-Qiang Zhang, Jian-Biao Chen, Cheng-Wei Wang, Ai-Zhen Liao and Xiao-Feng Su

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O 2 sensing dynamics of BiFeO 3 nanofibers: effect of minor carrier compensation

In this paper we investigate O 2 sensing dynamics in BiFeO 3 (BFO) nanofibers at various concentrations and temperatures, by using a combined experiment and computer simulation approach. Samples of pristine BFO, Ni-doped BFO, and Pb-doped BFO nanofibers were prepared. By incorporating Ni and Pb, additional acceptor states are introduced in BFO. Density functional theory calculations show that Ni prefers to substitute Fe site while Pb substitutes Bi site, resulting in a new deep donor originating from Ni interstitial defects, along with oxygen vacancies (V o ). We find that both the sensing response and recovery time are shorter in samples made of pristine BFO nanofibers than in Ni- and Pb-doped nanofiber samples. We interpret the observed sensing dynamics through charge transport theory of the major (acceptors) and minor (donors) carriers, and found that the minor carrier compensation plays a significant role in determining the response and recovery t...

Mushtaq Sobhan, Qiang Xu, Akash Katoch, Franklin Anariba, Sang Sub Kim and Ping Wu

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Negative differential resistance in monolayer WTe 2 tunneling transistors

We report theoretical investigations of quantum transport in monolayer transition metal dichalcogenide (TMDC) tunneling field effect transistors (TFETs). Due to the specific electronic structure of TMDC ##IMG## [http://ift.tt/1Jn7YZk] {${\rm WT}{{{\rm e}}_{2}}$} , a transmission valley is found in the conduction band (CB). For a proper choice of the doping, gate and supply voltages the ##IMG## [http://ift.tt/1GnBakA] {${\rm WT}{{{\rm e}}_{2}}$} TFET can produce a giant negative differential resistance (NDR) with a peak to valley ratio as large as 10 3 . The mechanism of NDR is identified to be due to a transport-mode bottleneck, i.e., the band to band tunneling from the valence band of the source is partially blocked by a transmission valley of the CB of the drain. More generally, our calculations show that electronic structures of at lea...



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Bio-inspired artificial functional photocatalyst: biomimetic enzyme-like TiO 2 /reduced graphene oxide nanocomposite with excellent molecular recognition ability

An enzyme-like TiO 2 /reduced graphene oxide (enzyme-TiO 2 /rGO) nanocomposite with molecular recognition ability was fabricated by biomimicking the geometrical and chemical complementation of the enzyme and substrate. The anatase TiO 2 nanocrystals were densely dispersed on rGO nanosheets with close interfacial contacts. With geometrical and chemical matching of target molecules and memorized cavities, the adsorption capacity of enzyme-TiO 2 /rGO nanocomposites for 4-nitrophenol (4.71 mg g −1 ) is about six times that of control TiO 2 /rGO without the enzyme-like feature (0.79 mg g −1 ), and the enzyme-TiO 2 /rGO shows a relative selectivity coefficient of 7.24. Moreover, enzyme-TiO 2 /rGO exhibits molecular recognitive photocatalytic degradation for a particular contaminant. The results demonstrate that enzyme-substrate recognition provides a convenient and powerful basis on which to biomimic and ...

Wentao Li, Xule Pei, Fang Deng, Xubiao Luo, Fengcong Li and Yong Xiao

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GNeosomes: Highly Lysosomotropic Nanoassemblies for Lysosomal Delivery

ACS Nano

DOI: 10.1021/nn507382n

Ezequiel Wexselblatt, Jeffrey D. Esko and Yitzhak Tor

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Silicon Nanowire-Induced Maturation of Cardiomyocytes Derived from Human Induced Pluripotent Stem Cells

Nano Letters

DOI: 10.1021/nl502227a

Yu Tan, Dylan Richards, Ruoyu Xu, Skylar Stewart-Clark, Santhosh Kumar Mani, Thomas Keith Borg, Donald R. Menick, Bozhi Tian and Ying Mei

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Lattice-Strain-Induced Slow Electron Cooling Due to Quasi-Type-II Behavior in Type-I CdTe/ZnS Nanocrystals

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b02420

Sourav Maiti, Tushar Debnath, Partha Maity and Hirendra N. Ghosh

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Further Search for Hydroxyl Nests in Acid Dealuminated Zeolite Y

The Journal of Physical Chemistry C

DOI: 10.1021/jp511082v

Istvan Halasz, Eric Senderov, David H. Olson and Jian-Jie Liang

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Silver–Water Clusters: A Theoretical Description of Agn(H2O)m for n = 1–4; m = 1–4

The Journal of Physical Chemistry C

DOI: 10.1021/jp512556g

Roger C. Baetzold

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Comprehensive Investigation of the Na3V2(PO4)2F3–NaV2(PO4)2F3 System by Operando High Resolution Synchrotron X-ray Diffraction

Chemistry of Materials

DOI: 10.1021/acs.chemmater.5b00361

M. Bianchini, F. Fauth, N. Brisset, F. Weill, E. Suard, C. Masquelier and L. Croguennec

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Effect of the B-Site Composition on the Oxygen Permeability and the CO2 Stability of Pr0.6Sr0.4CoxFe1–xO3−δ (0.0 ≤ x ≤ 1.0) Membranes

Chemistry of Materials

DOI: 10.1021/acs.chemmater.5b00166

Kaveh Partovi, Benjamin Geppert, Fangyi Liang, Claus H. Rüscher and Jürgen Caro

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Simple Analytical Expression for the Peak-Frequency Shifts of Plasmonic Resonances for Sensing

Nano Letters

DOI: 10.1021/acs.nanolett.5b00771

Jianji Yang, Harald Giessen and Philippe Lalanne

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Single-Crystalline Aluminum Nanostructures on a Semiconducting GaAs Substrate for Ultraviolet to Near-Infrared Plasmonics

ACS Nano

DOI: 10.1021/nn5070887

Hsuan-Wei Liu, Fan-Cheng Lin, Shi-Wei Lin, Jau-Yang Wu, Bo-Tsun Chou, Kuang-Jen Lai, Sheng-Di Lin and Jer-Shing Huang

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CO2 Electrochemical Reduction to Methane and Methanol on Copper-Based Alloys: Theoretical Insight

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b01574

Pussana Hirunsit, Wiwaporn Soodsawang and Jumras Limtrakul

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Wettability of Graphene-Coated Surface: Free Energy Investigations Using Molecular Dynamics Simulation

The Journal of Physical Chemistry C

DOI: 10.1021/jp511036e

Shih-Wei Hung, Pai-Yi Hsiao, Chien-Pin Chen and Ching-Chang Chieng

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Polyaniline-Coated Mesoporous Carbon/Sulfur Composites for Advanced Lithium Sulfur Batteries

The Journal of Physical Chemistry C

DOI: 10.1021/jp511846z

Xiaohui Zhao, Hyo-Jun Ahn, Ki-Won Kim, Kwon-Koo Cho and Jou-Hyeon Ahn

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Changing the Sign of Exchange Interaction in Radical Pairs to Tune Magnetic Field Effect on Electrogenerated Chemiluminescence

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b01541

Haiping Pan, Yan Shen, Lin Luan, Kai Lu, Jiashun Duan and Bin Hu

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Ultrastable Suspensions of Polyoxazoline-Functionalized ZnO Single Nanocrystals

Chemistry of Materials

DOI: 10.1021/acs.chemmater.5b00252

Giulia Morgese, Valerio Causin, Michele Maggini, Stefano Corrà, Silvia Gross and Edmondo M. Benetti

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Correction to M13 Virus-Enabled Synthesis of Titanium Dioxide Nanowires for Tunable Mesoporous Semiconducting Networks

Chemistry of Materials

DOI: 10.1021/acs.chemmater.5b01070

Po-Yen Chen, Xiangnan Dang, Matthew T. Klug, Noémie-Manuelle Dorval Courchesne, Jifa Qi, Md Nasim Hyder, Angela M. Belcher and Paula T. Hammond

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