APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

27 Feb 2012

Volume 100, Issue 9, Articles (09xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 100, 093101 (2012); http://dx.doi.org/10.1063/1.3687190 (4 pages)

Jinhai Mao, Li Huang, Yi Pan, Min Gao, Junfeng He, Haitao Zhou, Haiming Guo, Yuan Tian, Qiang Zou, Lizhi Zhang, Haigang Zhang, Yeliang Wang, Shixuan Du, Xingjiang Zhou, A. H. Castro Neto, et al.
Enlarge Image | Read More
Page 3 of 4 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Enhanced thermoelectric performance of graphene nanoribbons

H. Zheng, H. J. Liu, X. J. Tan, H. Y. Lv, L. Pan, J. Shi, and X. F. Tang

Appl. Phys. Lett. 100, 093104 (2012); http://dx.doi.org/10.1063/1.3689780 (5 pages) | Cited 3 times

Online Publication Date: 28 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thermoelectric properties of a series of armchair and zigzag graphene nanoribbons with narrow width are examined using nonequilibrium Green function method and molecular dynamics simulations. It is found that these nanoribbons are rather stable when the edge atoms are passivated by hydrogen and those with armchair edges exhibit much better thermoelectric performance than their zigzag counterparts. Moreover, the corresponding ZT value increases with decreasing ribbon width. By optimizing the doping level, a room temperature ZT of 6.0 can be achieved for the narrowest armchair nanoribbon. The significantly enhanced ZT value makes armchair graphene nanoribbon a promising candidate for thermoelectric applications.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
73.63.Bd Nanocrystalline materials
81.07.Bc Nanocrystalline materials
61.72.up Other materials
61.48.Gh Structure of graphene

Modulating quantum transport by transient chaos

Rui Yang, Liang Huang, Ying-Cheng Lai, and Louis M. Pecora

Appl. Phys. Lett. 100, 093105 (2012); http://dx.doi.org/10.1063/1.3690046 (4 pages) | Cited 4 times

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a scheme to modulate quantum transport in nanostructures based on classical chaos. By applying external gate voltage to generate a classically forbidden region, transient chaos can be generated, and the escape rate associated with the underlying non-attracting chaotic set can be varied continuously by adjusting the gate voltage. We demonstrate that this can effectively modulate the quantum conductance-fluctuation patterns. A theory based on self-energies and the spectrum of the generalized non-Hermitian Hamiltonian of the open quantum system is developed to understand the modulation mechanism.
Show PACS
73.21.La Quantum dots
73.63.Kv Quantum dots
81.07.Ta Quantum dots

Nonvolatile memory with graphene oxide as a charge storage node in nanowire field-effect transistors

David J. Baek, Myeong-Lok Seol, Sung-Jin Choi, Dong-Il Moon, and Yang-Kyu Choi

Appl. Phys. Lett. 100, 093106 (2012); http://dx.doi.org/10.1063/1.3690670 (4 pages) | Cited 2 times

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Through the structural modification of a three-dimensional silicon nanowire field-effect transistor, i.e., a double-gate FinFET, a structural platform was developed which allowed for us to utilize graphene oxide (GO) as a charge trapping layer in a nonvolatile memory device. By creating a nanogap between the gate and the channel, GO was embedded after the complete device fabrication. By applying a proper gate voltage, charge trapping, and de-trapping within the GO was enabled and resulted in large threshold voltage shifts. The employment of GO with FinFET in our work suggests that graphitic materials can potentially play a significant role for future nanoelectronic applications.
Show PACS
85.30.Tv Field effect devices
84.30.Sk Pulse and digital circuits

How does folding modulate thermal conductivity of graphene?

Nuo Yang, Xiaoxi Ni, Jin-Wu Jiang, and Baowen Li

Appl. Phys. Lett. 100, 093107 (2012); http://dx.doi.org/10.1063/1.3690871 (4 pages) | Cited 4 times

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study thermal transport in folded graphene nanoribbons using molecular dynamics simulations and the non-equilibrium Green’s function method. It is found that the thermal conductivity of flat graphene nanoribbons can be modulated by folding and changing interlayer couplings. The analysis of transmission reveals that the reduction of thermal conductivity is due to scattering of low frequency phonons by the folds. Our results suggest that folding can be utilized in the modulation of thermal transport properties in graphene and other two dimensional materials.
Show PACS
66.70.Lm Other systems such as ionic crystals, molecular crystals, nanotubes, etc.
63.22.Rc Phonons in graphene
65.80.Ck Thermal properties of graphene
73.63.Bd Nanocrystalline materials

Optical-force-induced bistability in nanomachined ring resonator systems

Y. F. Yu, J. B. Zhang, T. Bourouina, and A. Q. Liu

Appl. Phys. Lett. 100, 093108 (2012); http://dx.doi.org/10.1063/1.3690955 (4 pages) | Cited 4 times

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This paper reports optical-force-induced bistability in a nanomachined ring resonator system. It consists of two ring resonators and a bus waveguide, whereby each ring resonator has a free-hanging arc that is perpendicularly deformable by an optical force and changes the effective refractive index of the system. Therefore, an optical bistability is induced into the nanomachined ring resonator system, in which the bistability band can reach 0.3 nm and 0.68 nm in the ring resonators 1 and 2, respectively. It has potential applications in optical signal processing area, such as all-optical switching and opto-mechanical memory.
Show PACS
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
42.65.Pc Optical bistability, multistability, and switching, including local field effects
42.79.Gn Optical waveguides and couplers

Anisotropic capillary instability of silicon nanostructures under hydrogen anneal

T. Barwicz, G. M. Cohen, K. B. Reuter, S. Bangsaruntip, and J. W. Sleight

Appl. Phys. Lett. 100, 093109 (2012); http://dx.doi.org/10.1063/1.3690869 (3 pages) | Cited 1 time

Online Publication Date: 1 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Anneal in reduced pressure hydrogen ambient is known to induce morphological changes in silicon microstructures via markedly increased surface self-diffusivity on exposed silicon surfaces. Here, we investigate the capillary instability of silicon nanostructures under hydrogen anneal. We demonstrate that a surface diffusion mask can significantly improve stability by isolating vulnerable segments from large mass reservoirs. In addition, we find that Plateau-Rayleigh instability shows strong crystallographic dependence, which is explained by the surface energy anisotropy of silicon. We observe that nanowires are the least stable when their axial orientation corresponds to 〈100〉 and are increasingly stable for 〈111〉, 〈112〉, and 〈110〉.
Show PACS
68.03.Cd Surface tension and related phenomena
68.35.Fx Diffusion; interface formation
68.47.Fg Semiconductor surfaces
81.40.Gh Other heat and thermomechanical treatments
66.30.Pa Diffusion in nanoscale solids

Mass detection by means of the vibrating nanomechanical resonators

I. Stachiv, A. I. Fedorchenko, and Y.-L. Chen

Appl. Phys. Lett. 100, 093110 (2012); http://dx.doi.org/10.1063/1.3691195 (3 pages) | Cited 2 times

Online Publication Date: 1 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a theoretical analysis of the vibrating resonator in cantilever and bridge configurations operating as ultrasensitive mass sensors. An exact solution of the problem has been obtained. For the small mass ratio, the asymptotic solutions (which relate the frequency shift, mass ratio, and position of the attached particle) have been derived. It has been shown that the mass and position of the attached particle for the cantilever configuration can be unambiguously resolved by the use of three consecutive resonant frequencies. For the bridge configuration, the particle mass can be deduced by using only two measured resonant frequencies.
Show PACS
07.10.Cm Micromechanical devices and systems

Lateral positioning of InGaAs quantum dots using a buried stressor

A. Strittmatter, A. Schliwa, J.-H. Schulze, T. D. Germann, A. Dreismann, O. Hitzemann, E. Stock, I. A. Ostapenko, S. Rodt, W. Unrau, U. W. Pohl, A. Hoffmann, D. Bimberg, and V. Haisler

Appl. Phys. Lett. 100, 093111 (2012); http://dx.doi.org/10.1063/1.3691251 (3 pages) | Cited 2 times

Online Publication Date: 1 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a “bottom-up” approach for the lateral alignment of semiconductor quantum dots (QDs) based on strain-driven self-organization. A buried stressor formed by partial oxidation of (Al,Ga)As layers is employed in order to create a locally varying strain field at a GaAs(001) growth surface. During subsequent strained layer growth, local self-organization of (In,Ga)As QDs is controlled by the contour shape of the stressor. Large vertical separation of the QD growth plane from the buried stressor interface of 150 nm is achieved enabling high optical quality of QDs. Optical characterization confirms narrow QD emission lines without spectral diffusion.
Show PACS
81.07.Ta Quantum dots
68.65.Hb Quantum dots (patterned in quantum wells)
73.21.La Quantum dots
78.55.Cr III-V semiconductors
78.67.Hc Quantum dots

Scaling of Al2O3 dielectric for graphene field-effect transistors

B. Fallahazad, K. Lee, G. Lian, S. Kim, C. M. Corbet, D. A. Ferrer, L. Colombo, and E. Tutuc

Appl. Phys. Lett. 100, 093112 (2012); http://dx.doi.org/10.1063/1.3689785 (4 pages) | Cited 10 times

Online Publication Date: 1 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the scaling of Al2O3 dielectric on graphene by atomic layer deposition (ALD) using ultra-thin, oxidized Ti and Al films as nucleation layers. We show that the nucleation layer significantly impacts the dielectric constant (k) and morphology of the ALD Al2O3, yielding k = 5.5 and k = 12.7 for Al and Ti nucleation layers, respectively. Transmission electron microscopy shows that Al2O3 grown using the Ti interface is partially crystalline, while Al2O3 grown on Al is amorphous. Using a spatially uniform 0.6 nm-thick Ti nucleation layer, we demonstrate graphene field-effect transistors with top dielectric stacks as thin as 2.6 nm.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
85.30.Tv Field effect devices
85.65.+h Molecular electronic devices
77.22.Ch Permittivity (dielectric function)

Quasi first-principles Monte Carlo modeling of energy dissipation by low-energy electron beams in multi-walled carbon nanotube materials

Dimitris Emfietzoglou, Ioanna Kyriakou, Rafael Garcia-Molina, Isabel Abril, and Kostas Kostarelos

Appl. Phys. Lett. 100, 093113 (2012); http://dx.doi.org/10.1063/1.3688307 (5 pages) | Cited 2 times

Online Publication Date: 2 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The energy dissipation pattern of low-energy electron beams (0.3–30 keV) in multi-walled carbon nanotube (MWCNT) materials is studied by Monte Carlo simulation taking into account secondary-electron cascade generation. A quasi first-principles discrete-energy-loss model deduced from a dielectric response function description of electronic excitations in MWCNTs is employed whereby both single-particle and plasmon excitations are included in a unified and self-consistent manner. Our simulations provide practical analytical functions for computing depth-dose curves and charged-carrier generation volumes in MWCNT materials under low-energy electron beam irradiation.
Show PACS
71.20.Tx Fullerenes and related materials; intercalation compounds
73.22.Lp Collective excitations
71.15.-m Methods of electronic structure calculations
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Surface-dependent chemical properties of silicon nanowires: The acceleration of copper oxidation

Fan Liao, Shanshan Liu, Mingwang Shao, and Shuit-tong Lee

Appl. Phys. Lett. 100, 093114 (2012); http://dx.doi.org/10.1063/1.3691943 (4 pages) | Cited 1 time

Online Publication Date: 2 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
HF-treated silicon nanowires exhibited surface-dependent chemical property and accelerated the oxidation rate of copper with the enhancement factor of 10 000, confirmed by x-ray diffraction semi-quantitative analysis. This unexpected oxidation characteristic would make HF-treated silicon nanowires valuable for catalysis applications.
Show PACS
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
61.46.Np Structure of nanotubes (hollow nanowires)
81.65.Mq Oxidation

Metal-enhanced fluorescence: The role of quantum yield, Q0, in enhanced fluorescence

Anatoliy I. Dragan and Chris D. Geddes

Appl. Phys. Lett. 100, 093115 (2012); http://dx.doi.org/10.1063/1.3692105 (4 pages) | Cited 2 times

Online Publication Date: 2 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Metal-enhanced fluorescence has attracted enormous research and commercial interest in recent years, due to the ability to significantly enhance fluorescence signatures in the near-field as well as protect fluorophores against photobleaching. In this article, we address one of the major unresolved questions, whether far-field fluorophore quantum yield, Q0, has a direct relationship to fluorescence enhancement factors in metal-enhanced fluorescence.
Show PACS
78.55.Kz Solid organic materials

Photoresponse in epitaxial graphene with asymmetric metal contacts

Ram Sevak Singh, Venkatram Nalla, Wei Chen, Wei Ji, and Andrew T. S. Wee

Appl. Phys. Lett. 100, 093116 (2012); http://dx.doi.org/10.1063/1.3692107 (3 pages) | Cited 3 times

Online Publication Date: 2 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report photoresponse observations in epitaxial graphene (EG) devices with asymmetric metals (Au, Al) contacted in planar Au/EG/Al device format. The transient photocurrent measurements on the zero-bias device show photocurrent maxima at the Au/EG contact and minima at the EG/Al contact. This observed significant difference between the two types of junctions is responsible for the overall efficient device photoresponse. We have also found that the number of EG layers influences the photocurrent magnitude and response time regardless of incident photon energy or intensity. An external photoresponsivity (or efficiency) of ∼31.3 mA W−1 is achieved with a biased Au/EG/Al photodetector at excitation wavelength of 632.8 nm.
Show PACS
78.67.Wj Optical properties of graphene
73.50.Pz Photoconduction and photovoltaic effects
72.40.+w Photoconduction and photovoltaic effects
back to top
RSS Feeds
FREE

Efficiency enhancement of organic photovoltaics by addition of carbon nanotubes into both active and hole transport layer

Minas M. Stylianakis and Emmanuel Kymakis

Appl. Phys. Lett. 100, 093301 (2012); http://dx.doi.org/10.1063/1.3690056 (5 pages) | Cited 3 times

Online Publication Date: 27 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the effect of the incorporation of single walled carbon nanotubes (SWNTs) into both the active layer and the hole transport layer (HTL) on bulk heterojunction organic photovoltaic devices. The overall efficiency gain for such a device is 40%, compared with the pristine device. The observed efficiency gain is attributed to a more efficient exciton dissociation due to the SWNTs presence in the photoactive layer and an overall enhanced hole transport and collection through the SWNTs percolation paths, which are extended in both the active layer and the HTL.
Show PACS
88.40.jr Organic photovoltaics
88.40.hj Efficiency and performance of solar cells
FREE

A light emitting transistor based on a hybrid metal oxide-organic semiconductor lateral heterostructure

Zi-En Ooi, Thelese R. B. Foong, Samarendra P. Singh, Khai Leok Chan, and Ananth Dodabalapur

Appl. Phys. Lett. 100, 093302 (2012); http://dx.doi.org/10.1063/1.3689758 (3 pages) | Cited 1 time

Online Publication Date: 27 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A light-emitting field-effect transistor was fabricated, with its architecture based on a distinct heterojunction located midway between the source and drain contacts. Tetracene enabled hole transport on one side of the heterojunction (hole mobility ∼0.071 cm2/Vs), while amorphous solution-processed zinc tin oxide supported electron transport on the other side (electron mobility ∼0.81 cm2/Vs). The drain current vs. gate voltage curves of this device have a bell-shaped profile that is characteristic of lateral heterojunction bipolar field-effect transistors. The green light emission—from tetracene—closely follows the trend in drain current and is naked-eye visible in a darkened room.
Show PACS
85.30.Tv Field effect devices
FREE

Highly enhanced charge injection in thienoacene-based organic field-effect transistors with chemically doped contact

Takeo Minari, Peter Darmawan, Chuan Liu, Yun Li, Yong Xu, and Kazuhito Tsukagoshi

Appl. Phys. Lett. 100, 093303 (2012); http://dx.doi.org/10.1063/1.3690949 (4 pages) | Cited 4 times

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe the mechanism of contact resistance reduction and improvement in device performance of organic field-effect transistors by chemical doping at the contact interface. Insertion of iron(III)trichloride into the contact interface significantly reduced the contact resistance from 200 to 8.8 kΩ cm at a gate voltage of −40 V, and a field-effect mobility of 7.0 cm2/V s was achieved in devices based on dioctylbenzothienobenzothiophene. The improved charge injection is attributable to a reduction in the depletion layer thickness at the contact interface and occupation of trap states in the access region due to the generation of charge carriers by contact doping.
Show PACS
85.30.Tv Field effect devices
FREE

In-situ conductivity and Seebeck measurements of highly efficient n-dopants in fullerene C60

Torben Menke, Debdutta Ray, Jan Meiss, Karl Leo, and Moritz Riede

Appl. Phys. Lett. 100, 093304 (2012); http://dx.doi.org/10.1063/1.3689778 (4 pages) | Cited 13 times

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present two organic dimetal complexes Cr2(hpp)4 and W2(hpp)4 as n-dopants investigated in the model system of fullerene C60 for the application in organic electronic devices. Conductivity and Seebeck measurements on doped layers are carried out in vacuum at different doping concentrations and various substrate temperatures to compare the two dopants. Very high conductivities of up to 4 S/cm are achieved for both organic dopants. The thermal activation energy of the conductivity as well as the measured Seebeck coefficient are found to decrease with increasing doping concentration, indicating a shift of the Fermi level towards the electron transport level of the n-doped C60.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
61.72.U- Doping and impurity implantation
66.70.-f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves
FREE

Ultra-low voltage, organic thin film transistors fabricated on plastic substrates by a highly reproducible process

P. Cosseddu, S. Lai, M. Barbaro, and A. Bonfiglio

Appl. Phys. Lett. 100, 093305 (2012); http://dx.doi.org/10.1063/1.3691181 (5 pages) | Cited 3 times

Online Publication Date: 1 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Organic thin film transistors have been fabricated on plastic substrates using a combination of two ultrathin insulating films, namely a 6 nm Al2O3 film (grown by UV-Ozone treatment of a pre-deposited aluminium film) and a 25 nm parylene C film deposited by vapour phase, as gate dielectric. They show a very low leakage current density, around 2 × 10−9 A/cm2, and, most importantly, can be operated at voltages below 1 V. We demonstrate that this low-cost technique is highly reproducible and represents a step forward for the routine fabrication of ultra-low voltage plastic electronics.
Show PACS
85.30.Tv Field effect devices
back to top
RSS Feeds

Gate-all-around polycrystalline-silicon thin-film transistors with self-aligned grain-growth nanowire channels

Ta-Chuan Liao, Tsung-Kuei Kang, Chia-Min Lin, Chun-Yu Wu, and Huang-Chung Cheng

Appl. Phys. Lett. 100, 093501 (2012); http://dx.doi.org/10.1063/1.3691184 (3 pages)

Online Publication Date: 28 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, gate-all-around (GAA) polycrystalline silicon thin-film transistors (TFTs) with self-aligned grain-growth channels were fabricated using excimer laser crystallization (ELC) on a recessed-nanowire (RN) structure. Via the RN structure constructed by a simple sidewall-spacer formation, location-controlled nucleation and volume-confined lateral grain growth within the RN body during ELC process have been demonstrated with only one perpendicular grain boundary in each nanowire channel. Because of the high-crystallinity channel together with GAA operation mode, the proposed GAA-RN TFTs show good device integrity of lower threshold voltage, steeper subthreshold slope, and higher field-effect mobility as compared with the conventional planar counterparts.
Show PACS
85.30.Tv Field effect devices
61.46.Km Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires)
61.72.Mm Grain and twin boundaries

Dopant characterization in self-regulatory plasma doped fin field-effect transistors by atom probe tomography

H. Takamizawa, Y. Shimizu, Y. Nozawa, T. Toyama, H. Morita, Y. Yabuuchi, M. Ogura, and Y. Nagai

Appl. Phys. Lett. 100, 093502 (2012); http://dx.doi.org/10.1063/1.3690864 (3 pages) | Cited 1 time

Online Publication Date: 29 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fin field-effect transistors are promising next-generation electronic devices, and the identification of dopant positions is important for their accurate characterization. We report atom probe tomography (APT) of silicon fin structures prepared by a recently developed self-regulatory plasma doping (SRPD) technique. Trenches between fin-arrays were filled using a low-energy focused ion beam to directly deposit silicon, which allowed the analysis of dopant distribution by APT near the surface of an actual fin transistor exposed to air. We directly demonstrate that SRPD can achieve a boron concentration above 1 × 1020 atoms/cm3 at the fin sidewall.
Show PACS
85.30.Tv Field effect devices
85.40.Ry Impurity doping, diffusion and ion implantation technology
52.77.Dq Plasma-based ion implantation and deposition
back to top
RSS Feeds

On the origin of electrical conductivity in the bio-electronic material melanin

A. Bernardus Mostert, Ben J. Powell, Ian R. Gentle, and Paul Meredith

Appl. Phys. Lett. 100, 093701 (2012); http://dx.doi.org/10.1063/1.3688491 (3 pages) | Cited 5 times

Online Publication Date: 27 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The skin pigment melanin is one of a few bio-macromolecules that display electrical and photo-conductivity in the solid-state. A model for melanin charge transport based on amorphous semiconductivity has been widely accepted for 40 years. In this letter, we show that a central pillar in support of this hypothesis, namely experimental agreement with a hydrated dielectric model, is an artefact related to measurement geometry and non-equilibrium behaviour. Our results cast significant doubt on the validity of the amorphous semiconductor model and are a reminder of the difficulties of electrical measurements on low conductivity, disordered organic materials.
Show PACS
87.85.jc Electrical, thermal, and mechanical properties of biological matter
72.40.+w Photoconduction and photovoltaic effects
87.15.Pc Electronic and electrical properties

Ring like self assembled Ni nanoparticles based biosensor for food toxin detection

Prasanta Kalita, Jay Singh, Manish Kumar Singh, Pratima R. Solanki, G. Sumana, and B. D. Malhotra

Appl. Phys. Lett. 100, 093702 (2012); http://dx.doi.org/10.1063/1.3690044 (4 pages) | Cited 5 times

Online Publication Date: 28 February 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The self-assembled ring like nickel (RnNi ∼ 10-20 nm) nanoparticles have been prepared by pulsed laser ablation method and confirmed by transmission electron microscopy. These RnNi nanoparticles electrophoretically deposited onto the indium-tin-oxide (ITO) glass substrate have been functionalized with dimethyl sulfoxide (DMSO) for covalent immobilization of anti-aflatoxin (a-AfB1) monoclonal antibodies and bovine serum albumin as blocking agent. The electrochemical response studies of a-AfB1/DMSO/RnNi-film/ITO bioelectrode reveal linearity as 5-100 ngdL−1, detection limit of 32.7 ngdL−1, sensitivity of 0.59 μA/ng dL−1, and shelf-life of 60 days. The low value (1.3 × 1014 molL−1) of association constant (Ka) shows high affinity towards aflatoxin.
Show PACS
87.85.fk Biosensors
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
81.15.Fg Pulsed laser ablation deposition
81.16.Dn Self-assembly
81.16.Mk Laser-assisted deposition
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices

Bio-inspired signal transduction with heterogeneous networks of nanoscillators

Javier Cervera, José A. Manzanares, and Salvador Mafé

Appl. Phys. Lett. 100, 093703 (2012); http://dx.doi.org/10.1063/1.3691630 (4 pages)

Online Publication Date: 2 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Networks of single-electron transistors mimic some of the essential properties of neuron populations, because weak electrical signals trigger network oscillations with a frequency proportional to the input signal. Input potentials representing the pixel gray level of a grayscale image can then be converted into rhythms and the image can be recovered from these rhythms. Networks of non-identical nanoscillators complete the noisy transduction more reliably than identical ones. These results are important for signal processing schemes and could support recent studies suggesting that neuronal variability enhances the processing of biological information.
Show PACS
87.85.Ng Biological signal processing
85.35.Gv Single electron devices
87.19.L- Neuroscience
back to top
RSS Feeds

Is it effective to harvest visible light by decreasing the band gap of photocatalytic materials?

Ning Fu, Xinhu Tang, and Dongyang Li

Appl. Phys. Lett. 100, 093901 (2012); http://dx.doi.org/10.1063/1.3690052 (4 pages) | Cited 1 time

Online Publication Date: 1 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In situ variations in the electron work function and photo-current of TiO2 nanotubes demonstrate that long-wavelength illumination only has a minor effect on the excitation of electrons in the nanotubes after being exposed to short-wavelength light or when the short-wavelength light coexisted, indicating that the solar spectrum may not be utilized as efficiently as expected by extending the absorption spectrum of the photocatalytic material to visible light range with decreased band gaps.
Show PACS
72.40.+w Photoconduction and photovoltaic effects
73.22.-f Electronic structure of nanoscale materials and related systems
73.30.+y Surface double layers, Schottky barriers, and work functions
78.40.Fy Semiconductors
82.50.Hp Processes caused by visible and UV light
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Band-filling dependence of thermoelectric properties in B20-type CoGe

N. Kanazawa, Y. Onose, Y. Shiomi, S. Ishiwata, and Y. Tokura

Appl. Phys. Lett. 100, 093902 (2012); http://dx.doi.org/10.1063/1.3691260 (3 pages)

Online Publication Date: 2 March 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have synthesized B20-type Co1−xFexGe and Co1−yNiyGe by a high-pressure method and investigated the band-filling dependence of thermoelectric properties. CoGe shows a large figure of merit (ZT ≈ 0.11) due to its low resistivity and large negative Seebeck coefficient (S) (-82μV/K) at 300 K. The sign-crossover of S is observed with increasing Fe concentration. The Boltzmann transport model can explain semi-quantitatively the experimental results, from which we conclude that the large positive or negative S originates from the asymmetric band structure composed of the Dirac cone and the flat band with sharp bends around the Fermi energy.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
82.40.Fp Shock wave initiated reactions, high-pressure chemistry
62.50.-p High-pressure effects in solids and liquids
72.20.-i Conductivity phenomena in semiconductors and insulators
Page 3 of 4 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close