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

21 Mar 2011

Volume 98, Issue 12, Articles (12xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 98, 123101 (2011); http://dx.doi.org/10.1063/1.3567492 (3 pages)

Linus C. Chuang, Michael Moewe, Kar Wei Ng, Thai-Truong D. Tran, Shanna Crankshaw, Roger Chen, Wai Son Ko, and Connie Chang-Hasnain
Enlarge Image | Read More
Page 2 of 5 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Synthesis and phosphorescence mechanism of a reddish orange emissive long afterglow phosphor Sm3+-doped Ca2SnO4

Zhenghua Ju, Ruiping Wei, Jiangrong Zheng, Xiuping Gao, Shuihe Zhang, and Weisheng Liu

Appl. Phys. Lett. 98, 121906 (2011); http://dx.doi.org/10.1063/1.3567511 (3 pages) | Cited 12 times

Online Publication Date: 22 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A reddish orange emissive long afterglow phosphor Ca2SnO4:Sm3+ was prepared by solid-state reaction in air atmosphere and characterized by photoluminescence, long-lasting phosphoresce. The afterglow time is more than 7 h which is the longest red or reddish orange long afterglow phosphor at the present time. The phosphorescence mechanism of the long afterglow phosphor was studied by thermoluminescence and positron annihilation lifetime experiments. The defects VCa″, structure defects Sn3+ and Sn2+ may act as hole trapping centers while the defects SmCa⋅ may act as electron trapping centers, and trapping centers play an essential role for photoenergy storage in persistent phosphors.
Show PACS
78.55.Hx Other solid inorganic materials
78.60.Kn Thermoluminescence
71.55.Ht Other nonmetals
78.70.Bj Positron annihilation
81.20.-n Methods of materials synthesis and materials processing
61.72.jn Color centers

Optoelectronic properties of Al:ZnO: Critical dosage for an optimal transparent conductive oxide

Mirco Bazzani, Andrea Neroni, Arrigo Calzolari, and Alessandra Catellani

Appl. Phys. Lett. 98, 121907 (2011); http://dx.doi.org/10.1063/1.3567513 (3 pages) | Cited 6 times

Online Publication Date: 22 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study the effects of aluminum doping on the electronic and optical properties of ZnO, via density functional simulations. We discuss the bandstructure and absorption properties of Al:ZnO as a function of the dopant concentration, and compare with recent experimental data. Our results support the formation of a transparent conductive oxide compound up to an incorporation of Al of about 3% in substitutional Zn sites. We propose an explanation to the observed degradation of conductivity in terms of interstitial defects expected to occur at high doping concentrations, beyond the Al solubility limit.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
71.20.Nr Semiconductor compounds
71.15.Mb Density functional theory, local density approximation, gradient and other corrections
61.72.uj III-V and II-VI semiconductors

Dislocation engineering in SiGe heteroepitaxial films on patterned Si (001) substrates

R. Gatti, F. Boioli, M. Grydlik, M. Brehm, H. Groiss, M. Glaser, F. Montalenti, T. Fromherz, F. Schäffler, and Leo Miglio

Appl. Phys. Lett. 98, 121908 (2011); http://dx.doi.org/10.1063/1.3569145 (3 pages) | Cited 1 time

Online Publication Date: 22 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate dislocation engineering without oxide masks. By using finite element simulations we show how nanopatterning of Si substrates with {111} trenches provides anisotropic elastic relaxation in a SiGe film, generates preferential nucleation sites for dislocation loops, and allows for dislocation trapping, leaving wide areas free of threading dislocations. These predictions are confirmed by atomic force and transmission electron microscopy performed on overcritical Si0.7Ge0.3 films. These were grown by molecular beam epitaxy on a Si(001) substrate patterned with periodic arrays of selectively etched {111}-terminated trenches.
Show PACS
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
68.55.ag Semiconductors
81.16.Rf Micro- and nanoscale pattern formation
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.37.Lp Transmission electron microscopy (TEM)
68.37.Ps Atomic force microscopy (AFM)

Surface-adsorption-induced bending behaviors of graphene nanoribbons

Zuoqi Zhang, Bin Liu, Keh-Chih Hwang, and Huajian Gao

Appl. Phys. Lett. 98, 121909 (2011); http://dx.doi.org/10.1063/1.3569589 (3 pages) | Cited 9 times

Online Publication Date: 22 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate bending behaviors of graphene nanoribbons (GNRs) induced by surface adsorption of hydrogen atoms or molecules. At low adsorption coverage, it is shown that the chemical adsorption of hydrogen atoms causes a GNR to bend away from the adsorbed atoms while the physical adsorption of hydrogen molecules causes it to bend toward the adsorbed molecules. Interestingly, these trends are reversed at high adsorption coverage. There exists a range of linear responses for both chemical and physical adsorptions, which points to promising applications of GNRs as sensitive chemical-/biosensors.
Show PACS
81.40.Lm Deformation, plasticity, and creep
62.20.F- Deformation and plasticity
68.43.Mn Adsorption kinetics

Temperature dependent x-ray diffraction study of lightly doped NaxWO3

Sanhita Paul, G. D. Mukherjee, Anirudha Ghosh, S. Oishi, and Satyabrata Raj

Appl. Phys. Lett. 98, 121910 (2011); http://dx.doi.org/10.1063/1.3569716 (3 pages) | Cited 2 times

Online Publication Date: 22 March 2011

Full Text: Read Online (HTML) | Download PDF


See Also: Erratum

Show Abstract
Temperature dependent x-ray diffraction studies have been carried out on nonstoichiometric lightly doped sodium tungsten bronze (NaxWO3 for x = 0.025). The investigation reveals a structural modification around 230 K. Although the high and low temperature phases are monoclinic but at low temperature the corner sharing WO6 octahedra get significantly distorted due to displacement of tungsten and oxygen atoms from its mean position. This structural modification induces polaron formation in Na0.025WO3 below 230 K.
Show PACS
71.38.-k Polarons and electron-phonon interactions
61.72.Dd Experimental determination of defects by diffraction and scattering
61.72.up Other materials
79.60.Bm Clean metal, semiconductor, and insulator surfaces

The crystallization behavior of stoichiometric and off-stoichiometric Ga–Sb–Te materials for phase-change memory

Huai-Yu Cheng, Simone Raoux, and Jean L. Jordan-Sweet

Appl. Phys. Lett. 98, 121911 (2011); http://dx.doi.org/10.1063/1.3570636 (3 pages) | Cited 7 times

Online Publication Date: 23 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The stoichiometric Ga4Sb6Te3 and Ga–Sb materials were systemically studied. The alloy Ga4Sb6Te3 shows a fast crystallization speed, very high crystallization temperature, Tx, and high electrical contrast. Although stoichiometric GaSb has similar performance and even faster crystallization speed, the electrical contrast is much lower. The other off-stoichiometric compounds we studied all have higher Tx than Ge2Sb2Te5 indicating a good amorphous stability. By raising the Sb/Te ratio with GaSb incorporation, Tx and the recrystallization time of melt-quenched, amorphous samples can be effectively increased. The stoichiometric Ga4Sb6Te3 with less likelihood of phase-segregation compared to nonstoichiometric compounds is a promising candidate for phase-change memory.
Show PACS
64.70.dg Crystallization of specific substances
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
81.40.Gh Other heat and thermomechanical treatments
61.66.Bi Elemental solids
61.66.Dk Alloys

Effect of strain on bond-specific reaction kinetics during the oxidation of H-terminated (111) Si

Bilal Gokce, David E. Aspnes, and Kenan Gundogdu

Appl. Phys. Lett. 98, 121912 (2011); http://dx.doi.org/10.1063/1.3567528 (3 pages) | Cited 2 times

Online Publication Date: 23 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Although strain is used in semiconductor technology for manipulating optical, electronic, and chemical properties of semiconductors, the understanding of the microscopic phenomena that are affected or influenced by strain is still incomplete. Second-harmonic generation data obtained during the air oxidation of H-terminated (111) Si reveal the effect of compressive strain on this chemical reaction. Even small amounts of strain manipulate the reaction kinetics of surface bonds significantly, with tensile strain enhancing oxidation and compressive strain retarding it. This dramatic change suggests a strain-driven charge transfer mechanism between Si–H up bonds and Si–Si back bonds in the outer layer of Si atoms.
Show PACS
82.30.Fi Ion-molecule, ion-ion, and charge-transfer reactions
81.40.Lm Deformation, plasticity, and creep
62.20.F- Deformation and plasticity
81.65.Mq Oxidation
81.05.Cy Elemental semiconductors
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

Enhanced visible and near-infrared optical absorption in silicon supersaturated with chalcogens

Si H. Pan, Daniel Recht, Supakit Charnvanichborikarn, James S. Williams, and Michael J. Aziz

Appl. Phys. Lett. 98, 121913 (2011); http://dx.doi.org/10.1063/1.3567759 (3 pages) | Cited 11 times

Online Publication Date: 23 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We show that single-crystal silicon supersaturated with sulfur (S), selenium (Se), or tellurium (Te) displays a substantially enhanced absorption coefficient for light with wavelengths of 400 to 1600 nm. Alloys were prepared in silicon on insulator wafers by ion implantation followed by nanosecond pulsed laser melting. Measurements of the absorption coefficient were made by direct transmission through freestanding thin films and by spectroscopic ellipsometry.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
61.72.uf Ge and Si
85.40.Ry Impurity doping, diffusion and ion implantation technology
64.70.dj Melting of specific substances
78.40.Fy Semiconductors

Superhard diamond/tungsten carbide nanocomposites

Z. J. Lin, J. Z. Zhang, B. S. Li, L. P. Wang, Ho-Kwang Mao, Russell J. Hemley, and Yusheng Zhao

Appl. Phys. Lett. 98, 121914 (2011); http://dx.doi.org/10.1063/1.3570645 (3 pages) | Cited 4 times

Online Publication Date: 24 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigated the processing conditions of diamond/tungsten carbide (WC) composites using in situ synchrotron x-ray diffraction (XRD) and reactive sintering techniques at high pressure and high temperatures. The as-synthesized composites were characterized by synchrotron XRD, scanning electron microscopy, high-resolution transmission electron microscopy, and indentation hardness measurements. Through tuning of the reaction temperature and time, we produced fully reacted, well-sintered, and nanostructured diamond composites with Vickers hardness of about 55 GPa and the grain size of WC binding matrix smaller than 50 nm. A specific set of orientation relationships between WC and tungsten is identified to gain microstructural insight into the reaction mechanism between diamond and tungsten.
Show PACS
81.16.-c Methods of micro- and nanofabrication and processing
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
62.20.Qp Friction, tribology, and hardness
62.50.-p High-pressure effects in solids and liquids
81.05.uj Diamond/nanocarbon composites

Direct observation of N-(group V) bonding defects in dilute nitride semiconductors using hard x-ray photoelectron spectroscopy

F. Ishikawa, S. Fuyuno, K. Higashi, M. Kondow, M. Machida, H. Oji, J.-Y. Son, A. Trampert, K. Umeno, Y. Furukawa, and A. Wakahara

Appl. Phys. Lett. 98, 121915 (2011); http://dx.doi.org/10.1063/1.3573789 (3 pages) | Cited 3 times

Online Publication Date: 25 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using bulk sensitive hard x-ray photoelectron spectroscopy, we directly observe a spectrum related to N–As bonding defects in (Ga,In)(N,As)/Ga(N,As) heterostructure. The defects are most likely attributed to split interstitials. Their concentration is in the order of 1019 cm−3, close to the detection limit of the measurement. Rapid thermal annealing eliminates the defects, leading to those undetectable. Similar phenomenon is observed for N–P bonding defects in In(N,P). The results indicate common features in dilute nitride semiconductor system: existence of N-(group V) bonding defects and their behavior on postgrowth annealing.
Show PACS
61.72.jj Interstitials
79.60.Jv Interfaces; heterostructures; nanostructures
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.72.Cc Kinetics of defect formation and annealing

Efficient blocking of planar defects by prismatic stacking faults in semipolar (11math2)-GaN layers on m-sapphire by epitaxial lateral overgrowth

B. Lacroix, M. P. Chauvat, P. Ruterana, G. Nataf, and P. de Mierry

Appl. Phys. Lett. 98, 121916 (2011); http://dx.doi.org/10.1063/1.3571455 (3 pages) | Cited 1 time

Online Publication Date: 25 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
For the next-generation solid state lighting, the production of high quality semipolar (11math2) GaN layers on sapphire obtained using asymmetric epitaxial lateral overgrowth (ELO) method has been investigated. This type of ELO leads to efficient blocking of the basal stacking faults (BSFs) in the bulk, and enables the formation of nondefective layers at the surface. The BSFs terminate due to generation of prismatic stacking faults along a well defined boundary. The corresponding intensity of GaN band edge photoluminescence emission is increased by more than four orders of magnitude in comparison to that from semipolar templates.
Show PACS
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.55.ag Semiconductors
61.72.Nn Stacking faults and other planar or extended defects
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.05.Ea III-V semiconductors

Scattering-based hole burning mediated by localized surface plasmon resonance in photoreactive random media containing Ag nanoparticles

Shunsuke Murai, Yutaka Fujimoto, Koji Iwata, Koji Fujita, and Katsuhisa Tanaka

Appl. Phys. Lett. 98, 121917 (2011); http://dx.doi.org/10.1063/1.3567929 (3 pages)

Online Publication Date: 25 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoreactive random media containing silver nanoparticles (Ag NPs) have been fabricated, and hole burning effects based on the interference of multiply scattered light have been investigated. Through the analysis of hole profiles, transport mean free path ℓ is estimated for the light with the wavelength of 585 nm. We find that ℓ in the samples embedded with Ag NPs is much shorter compared with that in a medium containing the same amount of titania (TiO2) NPs, indicating that Ag NPs scatter 585 nm lightwaves much stronger than TiO2 NPs because of their larger scattering cross sections due to the localized surface plasmon resonance.
Show PACS
78.47.nd Hole burning spectroscopy
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
78.35.+c Brillouin and Rayleigh scattering; other light scattering
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.68.+m Optical properties of surfaces
back to top
RSS Feeds

Anomalous on-current and subthreshold swing improvement in low-temperature polycrystalline-silicon thin-film transistors under Gate bias stress

Chia-Sheng Lin, Ying-Chung Chen, Ting-Chang Chang, Fu-Yen Jian, Hung-Wei Li, Yi-Chuan Chen, Te-Chih Chen, and Ya-Hsiang Tai

Appl. Phys. Lett. 98, 122101 (2011); http://dx.doi.org/10.1063/1.3568895 (3 pages)

Online Publication Date: 21 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This work investigates an improvement in anomalous on-current and subthreshold swing (SS) in Low-temperature polycrystalline-silicon thin-film transistors after positive gate bias stress. The experimental results reveal that the improved electric properties are due to the hole trapping at SiO2 above the lightly doped drain regions, which causes a strong electric field at the gate corners. The effect of the hole trapping is to reduce the effective channel length and the SS. Besides, the stress-related electric field was also simulated by TCAD software to verify the mechanism above.
Show PACS
85.30.Tv Field effect devices

Comprehensive study of the resistance switching in SrTiO3 and Nb-doped SrTiO3

X. G. Chen, X. B. Ma, Y. B. Yang, L. P. Chen, G. C. Xiong, G. J. Lian, Y. C. Yang, and J. B. Yang

Appl. Phys. Lett. 98, 122102 (2011); http://dx.doi.org/10.1063/1.3569586 (3 pages) | Cited 11 times

Online Publication Date: 21 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have demonstrated that the resistance switching (RS) effect can be controlled by the modification of the electrode configurations and the carrier densities in the Ag/SrTiO3 and Ag/Nb-doped SrTiO3(Nb:STO) structures. The elimination of the Schottky junction in the metal/Nb:STO completely destroys the RS effect, which suggests that the RS effect originates from the modification of Schottky-like barrier formed at the interface of metal/Nb:STO. The rectifying I-V curves revealed that the change in resistance was attributed to the trapping or detrapping carriers at the interface. The carrier density plays an important role in the determination of RS effect. The presence of the RS in SrTiO3 requires an appropriate doping level to provide conditions for trapping carriers at the interface.
Show PACS
73.40.Ns Metal-nonmetal contacts
73.40.Ei Rectification
73.30.+y Surface double layers, Schottky barriers, and work functions
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.60.+g Mixed conductivity and conductivity transitions

Characterization of the gate oxide of an AlGaN/GaN high electron mobility transistor

M. R. Holzworth, N. G. Rudawski, S. J. Pearton, K. S. Jones, L. Lu, T. S. Kang, F. Ren, and J. W. Johnson

Appl. Phys. Lett. 98, 122103 (2011); http://dx.doi.org/10.1063/1.3569715 (3 pages) | Cited 6 times

Online Publication Date: 21 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A subnanometer thick interfacial oxide layer present between the Ni/Au gate metal stack and semiconducting epilayers of an AlGaN/GaN high electron mobility transistor was characterized using high-angle annular dark-field scanning transmission electron microscopy and laser-assisted atom probe tomography. It was revealed that the oxide is composed of distinct Ni-oxide-rich and Al-oxide-rich layers with no Ga-oxide detected. The results provide information that is of potential importance in determining failure mechanisms and improving reliability of AlGaN/GaN high electron mobility transistors.
Show PACS
85.30.Tv Field effect devices

Observation of the photoinduced anomalous Hall effect in GaN-based heterostructures

C. M. Yin, N. Tang, S. Zhang, J. X. Duan, F. J. Xu, J. Song, F. H. Mei, X. Q. Wang, B. Shen, Y. H. Chen, J. L. Yu, and H. Ma

Appl. Phys. Lett. 98, 122104 (2011); http://dx.doi.org/10.1063/1.3569948 (3 pages) | Cited 2 times

Online Publication Date: 21 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The photocurrent has been measured in Al0.25Ga0.75N/GaN heterostructures at room temperature, and the photoinduced anomalous Hall effect (AHE) was observed. The AHE current changes linearly with the varied longitudinal electric fields. Due to the strong Rashba spin–orbit coupling of the two-dimensional electron gas in Al0.25Ga0.75N/GaN heterostructures, the intrinsic anomalous Hall mechanism is supposed to contribute to the photoinduced AHE. The photoinduced AHE measurement proposed in this study could be used to other spin related measurements at room temperature.
Show PACS
72.20.My Galvanomagnetic and other magnetotransport effects
72.25.-b Spin polarized transport
72.40.+w Photoconduction and photovoltaic effects
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect

Effect of channel thickness on density of states in amorphous InGaZnO thin film transistor

Sang Yeol Lee, Do Hyung Kim, Eugene Chong, Yong Woo Jeon, and Dae Hwan Kim

Appl. Phys. Lett. 98, 122105 (2011); http://dx.doi.org/10.1063/1.3570641 (3 pages) | Cited 9 times

Online Publication Date: 22 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the origin of threshold voltage shift with the thickness of amorphous InGaZnO channel layer deposited by rf magnetron sputter at room temperature, using density of states extracted from multi frequency method and falling rates of activation energy, which of trends are entirely consistent each other in respect of the reduction of total traps with increasing the channel thickness. Furthermore, we shows that the behavior of ΔVth under the positive gate bias stress and thermal stress can be explained by charge trapping mechanism based on total trap variation.
Show PACS
85.30.Tv Field effect devices

Strain-induced 0–π transition in a zigzag graphene nanoribbon Josephson junction

Jianfei Zou and Guojun Jin

Appl. Phys. Lett. 98, 122106 (2011); http://dx.doi.org/10.1063/1.3571280 (3 pages)

Online Publication Date: 23 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study theoretically the supercurrent through a superconductor/ferromagnetic zigzag graphene nanoribbon/superconductor junction by the Matsubara Green function method. The transformation of the supercurrent between the 0 and π states is remarkably realized in this Josephson junction by the combination of the uniaxial strain and gate-controlled barrier potential. Such strain-induced 0–π transition is found to result from the dependence of the effective Fermi velocity on the uniaxial strain in the graphene nanoribbon modulated by mechanical approaches.
Show PACS
74.50.+r Tunneling phenomena; Josephson effects
74.25.Sv Critical currents
74.78.Na Mesoscopic and nanoscale systems
74.40.Kb Quantum critical phenomena

Photoluminescence investigation of high quality GaAs1−xBix on GaAs

A. R. Mohmad, F. Bastiman, J. S. Ng, S. J. Sweeney, and J. P. R. David

Appl. Phys. Lett. 98, 122107 (2011); http://dx.doi.org/10.1063/1.3565244 (3 pages) | Cited 6 times

Online Publication Date: 23 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoluminescence (PL) of GaAs0.97Bi0.03 alloy was measured over a wide range of temperatures and excitation powers. Room temperature PL with peak wavelength of 1038 nm and full-width-half-maximum of 75 meV was observed which is relatively low for this composition. The improved quality is believed due to reduced alloy fluctuations by growing at relatively high temperature. The temperature dependence of PL peak energy indicated significant exciton localization at low temperatures. Furthermore, the band gap temperature dependence was found to be weaker than GaAs. An analysis of dominant carrier recombination mechanism(s) was also carried out indicating that radiative recombination is dominant at low temperature.
Show PACS
78.55.Cr III-V semiconductors
71.35.-y Excitons and related phenomena
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Tunable electronic transport properties of DyScO3/SrTiO3 polar heterointerface

D. F. Li, Yan Wang, and J. Y. Dai

Appl. Phys. Lett. 98, 122108 (2011); http://dx.doi.org/10.1063/1.3570694 (3 pages) | Cited 2 times

Online Publication Date: 24 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electronic transport properties of DyScO3/SrTiO3 polar heterointerface grown at different oxygen pressures are studied. This DyScO3/SrTiO3 polar heterointerface exhibits much higher charge mobility, up to 104 cm2 V−1 s−1, compared to the LaAlO3/SrTiO3 system due to relatively lower lattice mismatch between the film and substrate. More significantly, the DyScO3 film deposited under 10−4 mbar oxygen pressure presents an interfacial metal-to-semiconductor conducting mechanism transition at 90 K. Field effect transport measurement results reveal that this transition can be modulated by field effect through controlling the electron doping level of the interface originated from interfacial electronic reconstruction.
Show PACS
73.40.-c Electronic transport in interface structures
72.60.+g Mixed conductivity and conductivity transitions
71.30.+h Metal-insulator transitions and other electronic transitions
73.20.At Surface states, band structure, electron density of states
73.61.Ng Insulators
73.50.Dn Low-field transport and mobility; piezoresistance

Stable high conductive amorphous InGaZnO driven by hydrogenation using hot isostatic pressing

Won-Kyung Kim, Seunghun Lee, Yong Chan Cho, Hideomi Koinuma, Se-Young Jeong, Jong Moon Shin, Chae Ryong Cho, Jong-Seong Bae, Tae-Young Kim, and Sungkyun Park

Appl. Phys. Lett. 98, 122109 (2011); http://dx.doi.org/10.1063/1.3567635 (3 pages)

Online Publication Date: 24 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We carried out hydrogen injection in amorphous InGaZnO (a-IGZO) by hot isostatic pressing (HIP) treatment under different pressures ranging from 10 to 1000 bar and investigated the stable site of hydrogen in a-IGZO. The HIP process efficiently injected hydrogen in the whole sample without the formation of indium clusters. Despite oxygen annealing, hydrogenated a-IGZO maintained a high electrical conductivity (n ∼ 1019 cm−3 and μ ∼ 16 cm2/V s) without any noticeable physical degradation. In this paper, we discuss the dependence of the preferential position of hydrogen in a-IGZO on the magnitude of pressure and its contribution on the electrical characteristics.
Show PACS
81.05.Gc Amorphous semiconductors
72.20.Fr Low-field transport and mobility; piezoresistance
72.80.Ng Disordered solids
81.65.-b Surface treatments
81.40.Gh Other heat and thermomechanical treatments

Role of ZrO2 incorporation in the suppression of negative bias illumination-induced instability in Zn–Sn–O thin film transistors

Bong Seob Yang, Myung Soo Huh, Seungha Oh, Ung Soo Lee, Yoon Jang Kim, Myeong Sook Oh, Jae Kyeong Jeong, Cheol Seong Hwang, and Hyeong Joon Kim

Appl. Phys. Lett. 98, 122110 (2011); http://dx.doi.org/10.1063/1.3571448 (3 pages) | Cited 11 times

Online Publication Date: 25 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thin film transistors (TFTs) with In and Ga-free multicomponent Zn–Sn–Zr–O (ZTZO) channel layers were fabricated using the cosputtering approach. The incorporation of ZrO2 into the Zn–Sn–O (ZTO) films increased the contact resistance, which led to the degradation of the transport properties. In contrast, the threshold voltage shift under negative bias illumination stress (NBIS) was largely improved from −12.5 V (ZTO device) to −4.2 V (ZTZO device). This improvement was attributed to the reduction in the oxygen vacancy defects in the ZTZO film, suggesting that the photoinduced transition from VO to VO2+ was responsible for the NBIS-induced instability.
Show PACS
85.30.Tv Field effect devices
81.15.Cd Deposition by sputtering

Atmospheric stability and doping protection of noble-metal intercalated graphene on Ni(111)

D. Marchenko, A. Varykhalov, A. Rybkin, A. M. Shikin, and O. Rader

Appl. Phys. Lett. 98, 122111 (2011); http://dx.doi.org/10.1063/1.3565248 (3 pages) | Cited 6 times

Online Publication Date: 25 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
It has recently been demonstrated that pentacene can serve as protection layer for graphene on SiC preserving the unique E(k) band dispersion after exposure to atmosphere and subsequent annealing in vacuum. We confirm the stability of the ideal graphene band dispersion but without any protection layer. We demonstrate this by angle-resolved photoemission for graphene on Ni(111) intercalated by a Au monolayer. Exposure to air does not carbidize or oxidize the Ni substrate or open an apparent gap in the graphene. Its doping state is not affected and the Rashba-type spin-orbit effect on the graphene π state is preserved.
Show PACS
73.22.Pr Electronic structure of graphene
79.60.-i Photoemission and photoelectron spectra
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
81.05.ue Graphene
back to top
RSS Feeds

Understanding the role played by Fe on the tuning of magnetocaloric effect in Tb5Si2Ge2

A. M. Pereira, A. M. dos Santos, C. Magen, J. B. Sousa, P. A. Algarabel, Y. Ren, C. Ritter, L. Morellon, M. R. Ibarra, and J. P. Araújo

Appl. Phys. Lett. 98, 122501 (2011); http://dx.doi.org/10.1063/1.3567920 (3 pages) | Cited 5 times

Online Publication Date: 21 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, it is shown that when replacing Ge by Fe in Tb5Si2Ge2 the structural transition still occurs and enhances the magnetocaloric effect (MCE) (up to 66%) with maximum of MCE at a critical Fe amount where the magnetic and structural transitions become fully coupled. It is observed that Fe concentration is able to mimic the effect of external pressure as it induces a complex microstructure, that tunes long range strain fields. This knowledge is crucial for the development of strategies toward materials with improved performance for efficient magnetic refrigeration applications.
Show PACS
75.30.Sg Magnetocaloric effect, magnetic cooling
64.70.K- Solid-solid transitions
81.30.Hd Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)

Tunneling magnetoresistance in epitaxial discontinuous Fe/MgO multilayers

A. García-García, J. A. Pardo, P. Štrichovanec, C. Magén, A. Vovk, J. M. De Teresa, G. N. Kakazei, Y. G. Pogorelov, L. Morellón, P. A. Algarabel, and M. R. Ibarra

Appl. Phys. Lett. 98, 122502 (2011); http://dx.doi.org/10.1063/1.3569149 (3 pages) | Cited 2 times

Online Publication Date: 21 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial discontinuous Fe/MgO multilayers have been grown by pulsed laser deposition on MgO(001) single-crystal substrates. The multilayers with 0.6 nm nominal Fe layers thickness are superparamagnetic and demonstrate tunneling magnetoresistance (TMR) in the current-in-plane configuration. Increasing deposition temperature causes an improvement in crystal quality and is accompanied by higher TMR ratios. The maximum value (9.2% TMR at room temperature and 18 kOe magnetic field) trebles that of polycrystalline samples deposited simultaneously on glass substrates. A model formula for TMR ratio that includes both spin-dependent tunneling and spin-filtering effect is proposed to explain these results.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.20.-g Diamagnetism, paramagnetism, and superparamagnetism
81.15.Fg Pulsed laser ablation deposition
68.65.Ac Multilayers
75.50.Tt Fine-particle systems; nanocrystalline materials
75.47.-m Magnetotransport phenomena; materials for magnetotransport
Page 2 of 5 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close