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

30 Apr 2012

Volume 100, Issue 18, Articles (18xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 100, 181901 (2012); http://dx.doi.org/10.1063/1.4705414 (4 pages)

Etienne Brasselet, Arnaud Royon, and Lionel Canioni
Enlarge Image | Read More
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Band gap engineering in BiNbO4 for visible-light photocatalysis

B. C. Wang, J. Nisar, B. Pathak, T. W. Kang, and R. Ahuja

Appl. Phys. Lett. 100, 182102 (2012); http://dx.doi.org/10.1063/1.4709488 (5 pages) | Cited 2 times

Online Publication Date: 30 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the electronic structure of anionic mono- (S, N, and C) and co-doping (N-N, C-N, S-C, and S-N) on BiNbO4 for the visible-light photocatalysis. The maximum band gap reduction of pure BiNbO4 is possible with the (C-S) co-doping and minimum with N mono-doping. The calculated binding energies show that the co-doped systems are more stable than their mono-doped counterparts. Our optical absorption curves indicate that the mono- (C) and co-anionic doped (N-N and C-S) BiNbO4 systems are promising materials for visible light photocatalysis.
Show PACS
71.20.Ps Other inorganic compounds
78.30.Hv Other nonmetallic inorganics
78.40.Ha Other nonmetallic inorganics
82.50.Hp Processes caused by visible and UV light
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
71.15.Nc Total energy and cohesive energy calculations

Suppress temperature instability of InGaZnO thin film transistors by N2O plasma treatment, including thermal-induced hole trapping phenomenon under gate bias stress

Geng-Wei Chang, Ting-Chang Chang, Jhe-Ciou Jhu, Tsung-Ming Tsai, Yong-En Syu, Kuan-Chang Chang, Ya-Hsiang Tai, Fu-Yen Jian, and Ya-Chi Hung

Appl. Phys. Lett. 100, 182103 (2012); http://dx.doi.org/10.1063/1.4709417 (3 pages) | Cited 2 times

Online Publication Date: 2 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An abnormal subthreshold leakage current is observed at high temperature, which causes a notable stretch-out phenomenon in amorphous InGaZnO thin film transistors (a-IGZO TFTs). This is due to trap-induced thermal-generated holes accumulating at the source region, which leads to barrier lowering on the source side and causes an apparent subthreshold leakage current. In order to obtain superior thermal stability performance of a-IGZO TFTs, conducting N2O plasma treatment on active layer was expected to avert defects generation during SiO2 deposition process. Reducing defects generation not only suppresses subthreshold current stretch-out phenomenon but also significantly improves the bias stress stability in a-IGZO TFTs at high temperature.
Show PACS
85.30.Tv Field effect devices

Plasmon-enhanced mid-infrared luminescence from polar and lattice-structure-mismatched CdTe/PbTe single heterojunctions

Chunfeng Cai, Shuqiang Jin, Huizhen Wu, Bingpo Zhang, Lian Hu, and P. J. McCann

Appl. Phys. Lett. 100, 182104 (2012); http://dx.doi.org/10.1063/1.4711042 (5 pages) | Cited 1 time

Online Publication Date: 2 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose by exploring CdTe/PbTe single heterojunctions (SHs) that the abnormal enhancement of mid-infrared light emission from CdTe/PbTe heterostructures is due to coupling with surface plasmons. It is discovered that the observed intense mid-infrared luminescence in the SHs comes from the inherent polar interface character and coupling of surface plasmons localized at the metallic CdTe/PbTe interface to light emitted from the narrow gap PbTe. The finding offers an approach to manipulate mid-infrared light and to fabricate improved mid-infrared optoelectronic devices.
Show PACS
78.55.Hx Other solid inorganic materials
61.66.Fn Inorganic compounds
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Reduced longitudinal optical phonon-exciton interaction in InGaN/GaN nanorod structures

P. Renwick, H. Tang, J. Bai, and T. Wang

Appl. Phys. Lett. 100, 182105 (2012); http://dx.doi.org/10.1063/1.4711210 (4 pages)

Online Publication Date: 3 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoluminescence measurements have been performed on a series of InGaN/GaN multiple quantum well (MQW) nanorod array structures in order to investigate the influence of a nanorod structure on longitudinal optical (LO) phonon-exciton interaction. The nanorod array structures were fabricated on InGaN/GaN MQW epi-wafers using a self-organised Ni nano-mask technique. Compared with their corresponding as-grown samples, all the nanorod structures exhibit a significant reduction in Huang-Rhys factor, indicating a reduced coupling between LO-phonon and exciton. This is attributed to strain relaxation as a result of being fabricated into nanorod structures. Our excitation power dependent measurements have demonstrated that the nanorod structures exhibit a clear reduction in efficiency droop at a high excitation power. This proves a theoretical prediction previously reported, namely, LO-phonon-exciton coupling contributes to an indirect Auger recombination, leading to the efficiency droop of InGaN/GaN based emitters. The nanorod structures offering a reduced phonon-exciton coupling can pave the way for reducing or eliminating efficiency droop, one of the major challenges in the field of III-nitride optoelectronics.
Show PACS
81.16.-c Methods of micro- and nanofabrication and processing
61.46.-w Structure of nanoscale materials
63.20.kk Phonon interactions with other quasiparticles
78.55.Cr III-V semiconductors
78.67.De Quantum wells
68.65.Fg Quantum wells

In-situ oxygen x-ray absorption spectroscopy investigation of the resistance modulation mechanism in LiNbO2 memristors

Jordan D. Greenlee, Cole F. Petersburg, W. Laws Calley, Cherno Jaye, Daniel A. Fischer, Faisal M. Alamgir, and W. Alan Doolittle

Appl. Phys. Lett. 100, 182106 (2012); http://dx.doi.org/10.1063/1.4709422 (4 pages) | Cited 1 time

Online Publication Date: 4 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In situ near edge x-ray absorption fine structure spectroscopy (NEXAFS) is performed on LiNbO2 analog memristors to identify the underlying analog resistance modulation mechanism. Empty electronic state gradients in the NEXAFS difference spectra are observed in biased devices indicating a gradual movement of lithium. This movement of lithium supports the assertion that simple ion dopant drift and diffusion dominate the analog memristor’s resistance response. By identifying the physical memristance mechanism in analog LiNbO2 memristors, suggestions are made for additions to the memristor to modify device performance for both neuromorphic computing and memory applications.
Show PACS
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)
78.70.Dm X-ray absorption spectra
back to top
RSS Feeds

Nanowire arrays, surface anisotropy, magnetoelastic effects and spintronics

C. Tannous, A. Ghaddar, and J. Gieraltowski

Appl. Phys. Lett. 100, 182401 (2012); http://dx.doi.org/10.1063/1.4709427 (4 pages)

Online Publication Date: 1 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Resonance field Hres variation obtained from ferromagnetic resonance measurements performed versus field angle on ferromagnetic nickel nanowire arrays with different diameters (15 nm to 100 nm) and with temperature varying from liquid helium (4.2 K) to room value indicate presence of large surface anisotropy for small diameter (<50 nm) and strong magnetoelastic effects for all diameters. Extracting this information from temperature variation of anisotropy terms allows us to infer that magnetoelastic behavior versus temperature and nanowire diameter might have important implications for the design of nanowire based spintronic devices such as magnetic racetrack memory, logic and storage media, and devices.
Show PACS
81.05.Bx Metals, semimetals, and alloys
81.07.Gf Nanowires
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
75.80.+q Magnetomechanical effects, magnetostriction
75.50.Cc Other ferromagnetic metals and alloys
75.30.Gw Magnetic anisotropy

Measurement and simulation of anisotropic magnetoresistance in single GaAs/MnAs core/shell nanowires

J. Liang, J. Wang, A. Paul, B. J. Cooley, D. W. Rench, N. S. Dellas, S. E. Mohney, R. Engel-Herbert, and N. Samarth

Appl. Phys. Lett. 100, 182402 (2012); http://dx.doi.org/10.1063/1.4710524 (5 pages)

Online Publication Date: 1 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report four probe measurements of the low field magnetoresistance (MR) in single core/shell GaAs/MnAs nanowires (NWs) synthesized by molecular beam epitaxy, demonstrating clear signatures of anisotropic magnetoresistance that track the field-dependent magnetization. A comparison with micromagnetic simulations reveals that the principal characteristics of the magnetoresistance data can be unambiguously attributed to the nanowire segments with a zinc blende GaAs core. The direct correlation between magnetoresistance, magnetization, and crystal structure provides a powerful means of characterizing individual hybrid ferromagnet/semiconductor nanostructures.
Show PACS
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
75.50.Tt Fine-particle systems; nanocrystalline materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.A- Nucleation and growth

Spin-transfer switching in full-Heusler Co2FeAl-based magnetic tunnel junctions

Hiroaki Sukegawa, Zhenchao Wen, Kouta Kondou, Shinya Kasai, Seiji Mitani, and Koichiro Inomata

Appl. Phys. Lett. 100, 182403 (2012); http://dx.doi.org/10.1063/1.4710521 (5 pages) | Cited 2 times

Online Publication Date: 2 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrated spin-transfer magnetization switching using magnetic tunnel junctions (MTJs) with a full-Heusler alloy Co2FeAl (CFA). We prepared CFA (1.5 nm)/MgO/CoFe (4 nm) (“CFA-free”) and CFA (30 nm)/MgO/CoFeB (2 nm) (“CFA-reference”) MTJs on a Cr(001) layer. The intrinsic critical current density (Jc0) of the CFA-free (CFA-reference) MTJ was 29 MA/cm2 (7.1 MA/cm2). The larger Jc0 of the CFA-free MTJ is attributed to the significant enhancement of the Gilbert damping factor (∼0.04) of the CFA due to the Cr layer. The Jc0 of the CFA-reference is as small as that reported for typical CoFeB/MgO/CoFeB MTJs.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.30.Ds Spin waves
75.47.-m Magnetotransport phenomena; materials for magnetotransport
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
Author Select

Resonant microwave-to-spin-wave transducer

Y. Au, E. Ahmad, O. Dmytriiev, M. Dvornik, T. Davison, and V. V. Kruglyak

Appl. Phys. Lett. 100, 182404 (2012); http://dx.doi.org/10.1063/1.4711039 (5 pages) | Cited 4 times

Online Publication Date: 2 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We use time resolved scanning Kerr microscopy and analytical and numerical calculations to demonstrate coupling of uniform global microwave field to propagating spin waves for emerging magnonic architectures. The coupling is mediated by the local dynamic dipolar field produced by the magnetization of a resonantly driven all-metallic magnetic microwave-to-spin-wave transducer. The local dipolar field can exceed that of the incident microwave field by one order of magnitude. Our numerical simulations demonstrate the ability of the transducer to unidirectionally emit coherent exchange spin waves of nanoscale wavelengths with the emission direction programmed by the magnetic state of the transducer.
Show PACS
07.07.Mp Transducers
02.60.-x Numerical approximation and analysis
85.70.-w Magnetic devices

Room-temperature ferromagnetism in epitaxial Mg-doped SnO2 thin films

Ping Wu, Baozeng Zhou, and Wei Zhou

Appl. Phys. Lett. 100, 182405 (2012); http://dx.doi.org/10.1063/1.4711220 (4 pages) | Cited 3 times

Online Publication Date: 3 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magnetic behavior of epitaxial Mg-doped SnO2 thin films prepared by radio-frequency magnetron sputtering was investigated in this work. Room-temperature ferromagnetism with the saturation magnetization of about 6.9 emu/cm3 was observed in 6% Mg-doped SnO2 samples. And the saturation magnetization decreases when further doped to 8%, while the optical band-gap increases. The room-temperature ferromagnetism was induced by the holes created by Mg on the substitutional site. Additionally, Mg interstitials and oxygen vacancies play an important role in reducing the magnetic moments.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
81.15.Cd Deposition by sputtering
61.72.jj Interstitials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.50.Pp Magnetic semiconductors
75.30.Cr Saturation moments and magnetic susceptibilities

Vortex mode dynamics and bandwidth tunability in a two-dimensional array of interacting magnetic disks

Federico Montoncello and Loris Giovannini

Appl. Phys. Lett. 100, 182406 (2012); http://dx.doi.org/10.1063/1.4710549 (4 pages) | Cited 4 times

Online Publication Date: 4 May 2012

Full Text: Read Online (HTML) | Download PDF

multimedia


See Also: Erratum

Show Abstract
We calculate the spin wave spectrum and band diagram of a planar array of interacting disks in the vortex state at zero and finite applied field. We found that the circular polarization of modes depends on the Bloch wavevector k, and that the apparent spin wave profile can change as k increases from Γ to zone boundary as a consequence of the array periodicity, although the cell function remains the same. Focusing on the gyrotropic mode, we found that application of an external field can reduce or enhance the mode bandwidth, and hence slow down or boost the information carrier propagation along orthogonal directions.
Show PACS
75.30.Ds Spin waves
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Room temperature single GaN nanowire spin valves with FeCo/MgO tunnel contacts

Hyun Kum, Junseok Heo, Shafat Jahangir, Animesh Banerjee, Wei Guo, and Pallab Bhattacharya

Appl. Phys. Lett. 100, 182407 (2012); http://dx.doi.org/10.1063/1.4711850 (4 pages) | Cited 1 time

Online Publication Date: 4 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the direct measurement of spin transport characteristics in a GaN spin valve, with a relatively defect-free single GaN nanowire (NW) as the channel and FeCo/MgO as the tunnel barrier spin contact. Hanle spin precession and non-local transport measurements are made in an unintentionally doped nanowire spin valves. Spin diffusion length and spin lifetime values of 260 nm and 100 ps, respectively, are derived. Appropriate control measurements have been made to verify spin injection, transport, and detection.
Show PACS
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
back to top
RSS Feeds

Complete tailor-made inverse filter for image processing of scanning SQUID microscope

Masahiko Hayashi, Hiromichi Ebisawa, Ho Thanh Huy, and Takekazu Ishida

Appl. Phys. Lett. 100, 182601 (2012); http://dx.doi.org/10.1063/1.4709492 (4 pages)

Online Publication Date: 1 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
By introducing a numerical image processing technique, the resolution of scanning SQUID microscope (SSM) has been improved beyond the “naive” limit determined by the size of the pickup (sensor) coil. Our image processing is developed by taking account of the specific characteristics of SSM apparatus, including detailed shape of the coil and its perfect diamagnetism, in a tailor-made manner. The actual experiment has been done for nano-scale superconducting Pb network, and the magnetic field structures apparently smaller than the size of the pickup coil were made visible by our method.
Show PACS
42.30.Va Image forming and processing
85.25.Dq Superconducting quantum interference devices (SQUIDs)
07.79.-v Scanning probe microscopes and components

Critical-current reduction in thin superconducting wires due to current crowding

H. L. Hortensius, E. F. C. Driessen, T. M. Klapwijk, K. K. Berggren, and J. R. Clem

Appl. Phys. Lett. 100, 182602 (2012); http://dx.doi.org/10.1063/1.4711217 (4 pages) | Cited 9 times

Online Publication Date: 3 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate experimentally that the critical current in superconducting NbTiN wires is dependent on their geometrical shape, due to current-crowding effects. Geometric patterns such as 90∘ corners and sudden expansions of wire width are shown to result in the reduction of critical currents. The results are relevant for single-photon detectors as well as parametric amplifiers.
Show PACS
74.25.Sv Critical currents
74.70.Dd Ternary, quaternary, and multinary compounds (including Chevrel phases, borocarbides, etc.)
back to top
RSS Feeds

Large actuation and high dielectric strength in metallized dielectric elastomer actuators

Sze Hsien Low, Li Lynn Shiau, and Gih-Keong Lau

Appl. Phys. Lett. 100, 182901 (2012); http://dx.doi.org/10.1063/1.4709480 (4 pages) | Cited 1 time

Online Publication Date: 30 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Metal films are seldom used as compliant electrodes for dielectric elastomer actuator (DEA) because they tend to restrain deformation of soft dielectrics. This work showed that silver film electrodes formed by electroless deposition (ELD) are indeed stretchable, and the DEA using ELD silver electrodes is able to generate an actuation up to 50% areal strain. Such ELD silver electrodes can self-heal, remain conductive at up to 33% uni-axial strain, and do not stiffen the dielectric layer as much as the sputtered silver electrodes. This metallized DEA can sustain a high breakdown field up to 350 MV/m, which is good for generating a large actuation force.
Show PACS
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Defect chemistry of Ti-doped antiferroelectric Bi0.85Nd0.15FeO3

Ian M. Reaney, Ian MacLaren, Liqiu Wang, Bernhard Schaffer, Alan Craven, Kambiz Kalantari, Iasmi Sterianou, Shu Miao, Sarah Karimi, and Derek C. Sinclair

Appl. Phys. Lett. 100, 182902 (2012); http://dx.doi.org/10.1063/1.4705431 (3 pages) | Cited 1 time

Online Publication Date: 2 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Aberration corrected scanning transmission electron microscopy revealed that Bi0.85Nd0.15Fe0.9Ti0.1O3 ceramics contain coherent Nd-rich precipitates distributed throughout the perovskite lattice, implying charge compensation is obtained by the creation of VNd/// and not VBi///. At low concentrations, therefore, Ti4+ replace Fe2+ with the creation of 2/3VNd///, and at higher concentrations (when Fe2+ have been eliminated and the conductivity suppressed), Fe3+ with the creation of 1/3VNd///. The switch in ionic compensation mechanism from 2/3VNd/// at low Ti concentrations (∼1%) to 1/3VNd/// at higher concentrations (>1%) results in a decrease in the magnitude of ΔTC/Δx, as the disruption of long range anti-polar coupling declines.
Show PACS
77.80.B- Phase transitions and Curie point
66.30.H- Self-diffusion and ionic conduction in nonmetals
61.72.up Other materials
77.84.Cg PZT ceramics and other titanates
81.30.Mh Solid-phase precipitation
61.66.Fn Inorganic compounds
back to top
RSS Feeds

Large area Co nanoring arrays fabricated on silicon substrate by anodic aluminum oxide template-assisted electrodeposition

Y. L. Li, S. L Tang, W. B. Xia, L. Y. Chen, Y. Wang, T. Tang, and Y. W. Du

Appl. Phys. Lett. 100, 183101 (2012); http://dx.doi.org/10.1063/1.4709482 (4 pages) | Cited 2 times

Online Publication Date: 30 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A simple approach based on anodic aluminum oxide template-assisted electrodeposition was developed to fabricate large-area Co nanoring arrays on silicon substrate. The ring outer diameter and interspace can be modulated by varying the anodization parameters. Magnetic measurements and micromagnetic simulation revealed that the onion to vortex (O-V) transition is strongly diameter dependent. With increasing the outer diameter from 100 nm to 300 nm, the O-V switching field gradually changes from positive value to negative value. This was also proved by in situ observation of the magnetic states of the rings under different external fields using magnetic force microscope.
Show PACS
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
81.15.Pq Electrodeposition, electroplating
81.65.Mq Oxidation
82.45.Qr Electrodeposition and electrodissolution
75.75.Cd Fabrication of magnetic nanostructures

Effect of charge-transfer complex on the energy level alignment between graphene and organic molecules

Giyeol Bae, Hyun Jung, Noejung Park, Jinwoo Park, Suklyun Hong, and Wanjun Park

Appl. Phys. Lett. 100, 183102 (2012); http://dx.doi.org/10.1063/1.4709428 (4 pages) | Cited 1 time

Online Publication Date: 1 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We performed density-functional theory calculations to study the electronic structures at the interfaces between graphene and organic molecules that have been used in organic light-emitting diodes. In terms of work function, graphene itself is not favorable as either anode or cathode for commonly used electron or hole transport molecular species. However, the formation of charge transfer complex on the chemically inert sp2 carbon surface can provide a particular advantage. Unlike metal surfaces, the graphene surface remains non-bonded to electron-accepting molecules even after electron transfer, inducing an improved Fermi-level alignment with the highest-occupied-molecular-orbital level of the hole-injecting-layer molecules.
Show PACS
85.60.Jb Light-emitting devices
71.15.Mb Density functional theory, local density approximation, gradient and other corrections

Subwavelength nanopatterning of photochromic diarylethene films

Precious Cantu, Nicole Brimhall, Trisha L. Andrew, Rossella Castagna, Chiara Bertarelli, and Rajesh Menon

Appl. Phys. Lett. 100, 183103 (2012); http://dx.doi.org/10.1063/1.4710547 (3 pages)

Online Publication Date: 1 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The resolution of optical patterning is constrained by the far-field diffraction limit. In this letter, we describe an approach that exploits the unique photo- and electro-chemistry of diarylethene photochromic molecules to overcome this diffraction limit and achieve sub-wavelength nanopatterning.
Show PACS
82.50.-m Photochemistry
68.55.-a Thin film structure and morphology
78.20.-e Optical properties of bulk materials and thin films
78.66.Qn Polymers; organic compounds
81.16.Rf Micro- and nanoscale pattern formation
82.45.-h Electrochemistry and electrophoresis

Fabrication of white light-emitting diodes based on solvothermally synthesized copper indium sulfide quantum dots as color converters

Woo-Seuk Song and Heesun Yang

Appl. Phys. Lett. 100, 183104 (2012); http://dx.doi.org/10.1063/1.4711019 (4 pages) | Cited 9 times

Online Publication Date: 1 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A facile, large-scalable solvothermal synthesis of copper indium sulfide (CIS) quantum dots (QDs) and their application to the fabrication of QD-based white light-emitting diodes (LEDs) are reported. Depending on CIS QD growth time of 2 versus 5 h, the core/shell structured QDs of CIS/ZnS exhibit tunable emissions of yellow-orange with excellent quantum yields of 55%-91%. A white QD-LED is realized by applying CIS (2 h)/ZnS QD as a blue-to-yellow color converter. Furthermore, a white QD-LED having a blend of yellow and orange QDs is fabricated to improve a color rendering property through spectral extension, and its electroluminescent properties are evaluated.
Show PACS
85.60.Jb Light-emitting devices

Cascaded plasmon resonant field enhancement in nanoparticle dimers in the point dipole limit

Seyfollah Toroghi and Pieter G. Kik

Appl. Phys. Lett. 100, 183105 (2012); http://dx.doi.org/10.1063/1.4707159 (4 pages) | Cited 4 times

Online Publication Date: 2 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Cascaded field enhancement in silver dimer nanostructures is investigated using a dipole-dipole interaction model. Field enhancement spectra are evaluated as a function of the particle size difference and inter-particle spacing. We observe three distinct regimes of cascaded field enhancement: hindered cascading, multiplicative cascading, and the ultimate cascading limit, depending on the dimer interaction strength. Multiplicative cascading at small inter-particle spacing leads to analytic expressions for the ultimate internal and external field enhancement factors. For silver dimers in a host with index 1.5, we obtain a maximum internal field enhancement of 2.9 × 103, a factor of 75 larger than that of an isolated silver nanoparticle.
Show PACS
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons

Chemisorption on semiconductors: The role of quantum corrections on the space charge regions in multiple dimensions

Francesco Ciucci, Carlo de Falco, Marcelo I. Guzman, Sara Lee, and Tomonori Honda

Appl. Phys. Lett. 100, 183106 (2012); http://dx.doi.org/10.1063/1.4709483 (4 pages) | Cited 1 time

Online Publication Date: 3 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The chemisorption of O2 on nanoscale n-doped CdS semiconductors is computed in terms of a Wolkenstein isotherm coupled to the Schrödinger Poisson equation. Present numerical results show the dependence of the chemisorbed charge and the differential capacitance on oxygen partial pressure. A comparison against the classical Poisson-Boltzmann approach shows a higher chemisorbed charge in the quantum model, but a greater differential capacitance in the classical case.
Show PACS
68.43.Mn Adsorption kinetics
77.22.Jp Dielectric breakdown and space-charge effects

Transmission of electron through monolayer graphene laser barrier

C. Sinha and R. Biswas

Appl. Phys. Lett. 100, 183107 (2012); http://dx.doi.org/10.1063/1.4710525 (5 pages) | Cited 2 times

Online Publication Date: 3 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The present theoretical model deals with the transmission property of the Dirac fermions in the Floquet sidebands for the laser radiated graphene nanostructure. The laser assisted structure behaves as a tunneling barrier that leads to asymmetric transmission around the normal to the interface and is capable to confine the massless Dirac particles in a monolayer graphene strip. The absence of the Klein tunneling and the presence of a large number of controlling parameters would make the time dependent vector potential barrier superior over the electrostatic and magnetic barriers towards the opto-electronic device fabrication.
Show PACS
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.82.Ms Insulators
71.10.Fd Lattice fermion models (Hubbard model, etc.)

Exceptional high Seebeck coefficient and gas-flow-induced voltage in multilayer graphene

Xuemei Li, Jun Yin, Jianxin Zhou, Qin Wang, and Wanlin Guo

Appl. Phys. Lett. 100, 183108 (2012); http://dx.doi.org/10.1063/1.4707417 (4 pages) | Cited 2 times

Online Publication Date: 3 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Seebeck coefficient of graphene is an important parameter for defining its thermoelectric performance and thus practical applications, such as gas-flow-induced voltage. Here, we find a unique layer-dependence of the graphene Seebeck coefficient that exceptionally increases with increasing thickness to reach a peak value at six layers that is ∼77% higher than monolayer and ∼296% higher than graphite, unlike the monotonic decrease in electric resistance. However, the gas flow-induced voltage is significantly higher in 2, 4, 5, 6, and 7 layered graphene samples than in 1, 3, and 8 layered ones, against the prevailing wisdom that it should be proportional to Seebeck coefficient.
Show PACS
72.80.Vp Electronic transport in graphene
73.61.Wp Fullerenes and related materials
72.20.Pa Thermoelectric and thermomagnetic effects

Li-doped BC3 sheet for high-capacity hydrogen storage

Zailin Yang and Jun Ni

Appl. Phys. Lett. 100, 183109 (2012); http://dx.doi.org/10.1063/1.4711038 (4 pages) | Cited 1 time

Online Publication Date: 4 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Hydrogen storage on Li-doped BC3 sheet is studied by the first principles calculations. The Li atoms can be strongly adsorbed on the BC3 sheet without clustering. For one Li atom adsorbed on the (2 × 2) BC3 supercell, each Li atom could adsorb four hydrogen molecules. By adsorbing Li atoms on both sides of BC3 sheet to form the (1 × 1) pattern, the hydrogen capacity of 10.11 wt. % can be achieved and adsorption energy of each hydrogen molecule is in the range of 0.22–0.34 eV. The Li-doped BC3 sheet is the favorable candidate material for the reversible hydrogen adsorption and desorption at near ambient conditions.
Show PACS
88.30.R- Hydrogen storage
68.43.Mn Adsorption kinetics
68.43.Nr Desorption kinetics
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close