Strain-induced conduction gap in vertical devices made of misoriented graphene layers

We investigate the effects of uniaxial strain on the transport properties of vertical devices made of two misoriented (or twisted) graphene layers, which partially overlap each other. We find that because of the different orientations of the two graphene lattices, their Dirac points can be displaced and separated in the k -space by the effects of strain. Hence, a finite conduction gap as large as a few hundred meV can be obtained in the device with a small strain of only a few percent. The dependence of this conduction gap on the strain magnitude, strain direction, channel orientation and twist angle are clarified and presented. On this basis, the strong modulation of conductance and significant improvement of Seebeck coefficient are shown. The suggested devices therefore may be very promising for improving applications of graphene, e.g., as transistors or strain and thermal sensors.

V Hung Nguyen, Huy-Viet Nguyen, J Saint-Martin and P Dollfus

Click for full article

Arrays of quasi-hexagonally ordered silica nanopillars with independently controlled areal density, diameter and height gradients

A consecutive fabrication approach of independently tailored gradients of the topographical parameters distance, diameter and height in arrays of well-ordered nanopillars on smooth SiO 2 –Si-wafers is presented. For this purpose, previously reported preparation techniques are further developed and combined. First, self-assembly of Au-salt loaded micelles by dip-coating with computer-controlled pulling-out velocities and subsequent hydrogen plasma treatment produce quasi-hexagonally ordered, 2-dimensional arrays of Au nanoparticles (NPs) with unidirectional variations of the interparticle distances along the pulling direction between 50–120 nm. Second, the distance (or areal density) gradient profile received in this way is superimposed with a diameter-controlled gradient profile of the NPs applying a selective photochemical growth technique. For demonstration, a 1D shutter is used for locally defined UV exposure times to prepare Au NP size gradients varying between 12 an...

Burcin Özdemir, Wenting Huang, Alfred Plettl and Paul Ziemann

Click for full article

Flexible integrated circuits and multifunctional electronics based on single atomic layers of MoS 2 and graphene

Two-dimensional materials, such as graphene and its analogues, have been investigated by numerous researchers for high performance flexible and conformal electronic systems, because they offer the ultimate level of thickness scaling, atomically smooth surfaces and high crystalline quality. Here, we use layer-by-layer transfer of large area molybdenum disulphide (MoS 2 ) and graphene grown by chemical vapor deposition (CVD) to demonstrate electronics on flexible polyimide (PI) substrates. On the same PI substrate, we are able to simultaneously fabricate MoS 2 based logic, non-volatile memory cells with graphene floating gates, photo-detectors and MoS 2 transistors with tunable source and drain contacts. We are also able to demonstrate that these flexible heterostructure devices have very high electronic performance, comparable to four point measurements taken on SiO 2 substrates, with on/off ratios >10 7 and field effect mobiliti...

Matin Amani, Robert A Burke, Robert M Proie and Madan Dubey

Click for full article

Size-dependent mechanical properties of axial and radial mixed AlN/GaN nanostructure

In this paper, continuum multiscale models are proposed to describe the size-dependent mechanical properties of two kinds of heterogeneous nanostructures: radially heterogeneous nanowires and longitudinally heterogeneous nanolaminates. In both cases, the continuum models involve additional surface/interface energies, which allow capturing size effects. Several models of imperfect interface models, like coherent and spring-layer ones, are shown to respectively capture the size effects, which are reported by first-principles calculations performed on heterogeneous nanostructures. In each case, a procedure is proposed to identify the parameters of the surface/interface model in the continuum framework, based on first-principles calculations performed on slab systems. The obtained continuum models allow avoiding full computations on atomistic models, which are not affordable for large sizes (diameters, layer thickness). An increase of the overall stiffness for both kinds of heterogen...



Click for full article

Measuring the Heat Capacity of Large Isolated Molecules via Gas-Phase Collisions: C60

The Journal of Physical Chemistry C

DOI: 10.1021/jp512276e

Rongping Deng and Olof Echt

Click for full article

Design of Lead Telluride Based Thermoelectric Materials through Incorporation of Lead Sulfide Inclusions or Ligand Stripping of Nanosized Building Blocks

The Journal of Physical Chemistry C

DOI: 10.1021/jp5127046

Derak James, Xu Lu, Alexander Chi Nguyen, Donald Morelli and Stephanie L. Brock

Click for full article

Theoretical and Experimental Study of Anatase Nanotube Formation via Sodium Titanate Intermediates

The Journal of Physical Chemistry C

DOI: 10.1021/jp5110399

Marie-Christine Runkel, Olga Wittich, Armin Feldhoff, Michael Wark and Thomas Bredow

Click for full article

Comprehensive Study of Thermal Transport and Coherent Acoustic-Phonon Wave Propagation in Thin Metal Film–Substrate by Applying Picosecond Laser Pump–Probe Method

The Journal of Physical Chemistry C

DOI: 10.1021/jp512735k

Weigang Ma, Tingting Miao, Xing Zhang, Masamichi Kohno and Yasuyuki Takata

Click for full article

Layer-Dependent Modulation of Tungsten Disulfide Photoluminescence by Lateral Electric Fields

ACS Nano

DOI: 10.1021/nn506594a

Zhengyu He, Yuewen Sheng, Youmin Rong, Gun-Do Lee, Ju Li and Jamie H. Warner

Click for full article

Chemical and Electronic Structure Characterization of Lead Halide Perovskites and Stability Behavior under Different ExposuresA Photoelectron Spectroscopy Investigation

Chemistry of Materials

DOI: 10.1021/acs.chemmater.5b00348

Bertrand Philippe, Byung-Wook Park, Rebecka Lindblad, Johan Oscarsson, Sareh Ahmadi, Erik M. J. Johansson and Håkan Rensmo

Click for full article

Nanocrystalline Group IV Alloy Semiconductors: Synthesis and Characterization of Ge1–xSnx Quantum Dots for Tunable Bandgaps

Chemistry of Materials

DOI: 10.1021/cm503983b

Richard J Alan Esteves, Minh Q. Ho and Indika U. Arachchige

Click for full article

Hybrid, Tunable-Diameter, Metal Oxide Nanotubes for Trapping of Organic Molecules

Chemistry of Materials

DOI: 10.1021/cm503428q

Mohamed Salah Amara, Erwan Paineau, Stéphan Rouzière, Béatrice Guiose, Marie-Eve M. Krapf, Olivier Taché, Pascale Launois and Antoine Thill

Click for full article

Spectroscopic Signature of the Aggregation-Induced Emission Phenomena Caused by Restricted Nonradiative Decay: A Theoretical Proposal

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b01323

Tian Zhang, Huili Ma, Yingli Niu, Wenqiang Li, Dong Wang, Qian Peng, Zhigang Shuai and WanZhen Liang

Click for full article

In Situ Localized Surface Plasmon Resonance (LSPR) Spectroscopy to Investigate Kinetics of Chemical Bath Deposition of CdS Thin Films

The Journal of Physical Chemistry C

DOI: 10.1021/jp512738b

Humaira Taz, Rose Ruther, Abhinav Malasi, Sagar Yadavali, Connor Carr, Jagjit Nanda and Ramki Kalyanaraman

Click for full article

Charge Redistribution Effects on the UV–Vis Spectra of Small Ligated Gold Clusters: a Computational Study

The Journal of Physical Chemistry C

DOI: 10.1021/jp511120j

G. Lugo, V. Schwanen, B. Fresch and F. Remacle

Click for full article

Stepwise Reduction of Electrochemically Lithiated Core–Shell Heterostructures Based on the Prussian Blue Analogue Coordination Polymers K0.1Cu[Fe(CN)6]0.7·3.5H2O and K0.1Ni[Fe(CN)6]0.7·4.4H2O

Chemistry of Materials

DOI: 10.1021/cm503639a

Carissa H. Li, Marcus K. Peprah, Daisuke Asakura, Mark W. Meisel, Masashi Okubo and Daniel R. Talham

Click for full article

Mechanical Properties and Defect Sensitivity of Diamond Nanothreads

Nano Letters

DOI: 10.1021/nl5041012

Ruth E. Roman, Kenny Kwan and Steven W. Cranford

Click for full article

Mechanical Effects on the Electronic Properties of a Biphenyl-Based Molecular Switch

The Journal of Physical Chemistry C

DOI: 10.1021/jp510697a

Martin E. Zoloff Michoff, M. Ezequiel Castillo and Ezequiel P. M. Leiva

Click for full article

Electronic and Optical Properties of Graphene Quantum Dots: The Role of Many-Body Effects

The Journal of Physical Chemistry C

DOI: 10.1021/jp506969r

Yunhai Li, Huabing Shu, Shudong Wang and Jinlan Wang

Click for full article

Electronic Structure of Twisted Bilayers of Graphene/MoS2 and MoS2/MoS2

The Journal of Physical Chemistry C

DOI: 10.1021/jp507751p

Zilu Wang, Qian Chen and Jinlan Wang

Click for full article